Content uploaded by William C. Sullivan
All content in this area was uploaded by William C. Sullivan on Jul 10, 2014
Content may be subject to copyright.
ENVIRONMENT AND BEHAVIOR / January 2001Taylor et al. / COPING WITH ADD
COPING WITH ADD
The Surprising Connection
to Green Play Settings
ANDREA FABER TAYLOR is a doctoral candidate at the University of Illinois,
Urbana-Champaign. Her research focuses on the design of developmentally support
ive outdoor environments for children.
FRANCES E. KUO is an assistant professor and codirector of the Human-Environ
ment Research Laboratory at the University of Illinois, Urbana-Champaign. Her re
search focuses on attention, defensible space, and novice-friendly information.
WILLIAM C. SULLIVAN is an associate professor and codirector of the Human-
Environment Research Laboratory at the University of Illinois, Urbana-Champaign.
His research focuses on the psychological and social benefits of urban nature and on
citizen participation in environmental decision making.
ABSTRACT: Attention Restoration Theory suggests that contact with nature sup-
ports attentional functioning, and a number of studies have found contact with every-
day nature to be related to attention in adults. Is contact with everyday nature also
related to the attentional functioning of children? This question was addressed
through a study focusing on children with Attention Deficit Disorder (ADD). This
study examined the relationship between children’s nature exposure through leisure
activities and their attentional functioning using both within- and between-subjects
comparisons. Parents were surveyed regarding their child’s attentional functioning
after activities in several settings. Results indicate that children function better than
usual after activities in green settings and that the “greener” a child’s play area, the
less severe his or her attention deficit symptoms. Thus, contact with nature may sup
port attentional functioning in a population of children who desperately need
Over 2 million children in the United States alone are struggling to cope
with a chronic attentional deficit, Attention Deficit Disorder (ADD) (Barkley,
AUTHORS’ NOTE: This research was conducted in partial fulfillment of the require
ments for a doctoral degree in Natural Resources and Environmental Sciences at the
ENVIRONMENT AND BEHAVIOR, Vol. 33 No. 1, January 2001 54-77
© 2001 Sage Publications, Inc.
ADD reduces children’s attentional capacity and in doing so, has det
rimental effects on many aspects of life (e.g., school, interpersonal relation
ships, personal growth). Unfortunately, of the available treatments, some
have costly side effects, and the remaining have limited effectiveness. Sur
prisingly, the physical environment has not been examined as a potential
source of support for children with ADD. Attention Restoration Theory
(Kaplan, 1995) proposes that nature may support attentional functioning, and
a growing body of evidence indicates that, in adults with regular attentional
capacity, nature is supportive of attentional functioning. Could natural envi
ronments support attentional functioning in children with attention deficits?
The study presented here examined the effects of children’s afterschool and
weekend activity settings on their attention deficit symptoms.
In this section, we describe ADD and its treatment, review the previous
work on nature and attention, and present the central questions motivating
ATTENTION DEFICIT DISORDER
Attention Deficit Disorders are surprisingly common and have far reach-
ing consequences. ADD occurs in about 3% to 7% of school-age children
(Barkley, 1997; Bender, 1997; Hinshaw, 1994). Moreover, there is substan-
tial evidence that ADD in childhood can disrupt cognitive and social develop-
ment in several pivotal areas. First, children with ADD tend to have poor
academic performance (for reviews, see Barkley, 1997; Bender, 1997;
Hinshaw, 1994). Second, they are at increased risk for problems in the social
arena as well. For example, they tend to have poor peer relationships and are
often rejected by their peers (Alessandri, 1992; for reviews, see Bender,
1997; Berk, 1994; Hinshaw, 1994). They also tend to have poor relations with
their parents and have a higher rate of family conflict (Barkley,
Anastopoulos, Guevremont, & Fletcher, 1992). In addition, children with
ADD tend to display more aggressive and antisocial behavior (for reviews,
Taylor et al. / COPING WITH ADD 55
University of Illinois, Urbana-Champaign. This research was supported by a grant
from the National Urban and Community Forestry Advisory Council, and the Cooper
ative State Research, Education, and Extension Service, U.S. Department of Agricul
ture under Project No. ILLU-65-0387l. We thank all the parents who participated in
this research project, especially Patrick Sullivan. We also thank Dr. Lisa Monda-
Amaya, Dr. Annette Lansford, and Dr. William Stewart for their helpful suggestions.
Correspondence concerning this article should be addressed to Andrea Faber Taylor,
Human Environment Research Laboratory, University of Illinois, 1103 S. Dorner Dr.,
Urbana, IL 61801, or email@example.com.
see Barkley, 1997; Hinshaw, 1994). Perhaps it is not surprising, then, that
children with ADD are often also at greater risk for low self-esteem, anxiety, and
depression (for reviews, see Barkley, 1997; Bender, 1997; Hinshaw, 1994).
ADD is essentially defined as a developmental lag in the specific area of
attentional control. Thus, diagnosis involves evaluating a child’s attentional
control relative to their same-age peers (American Psychiatric Association,
1994). Specifically, the Diagnostic and Statistical Manual of Mental Disor
ders (DSM-IV) defines ADD as a persistent pattern of inattention “that is
more frequent and severe than is typically observed in individuals at a compa
rable level of development” (American Psychiatric Association, 1994, p. 78).
Barkley (1998) suggests that children with ADD can be expected to display
attentional control at a level 30% behind their same-age non-ADD peers; for
example, a 10-year-old ADD child generally displays behaviors more typical
of a 7-year-old child.
Current evidence suggests that this lag in attentional development is due
to biological factors (Barkley, 1995; Shue & Douglas, 1992). For example,
physiological recordings obtained through magnetic resonance imaging
show physical differences in the brain morphology of children with ADD.
Specifically, the right frontal lobe, which plays a key role in directed attention
(Foster, Eskes, & Stuss, 1994), was found to be smaller in children with ADD
(Hynd, Semrud-Clikeman, Lorys, Novey, & Eliopulos, 1990) than in chil-
dren with age-appropriate attentional control. Thus, although folk theory
holds that the immaturity of behaviors in ADD children is the product of
social factors such as poor parenting, the evidence suggests that ADD is a
biologically based disorder and not the product of the social or physical envi-
ronment (Barkley, 1998; National Institute of Mental Health [NIMH], 1994).
HOW IS ADD TREATED?
Current treatments for ADD are limited in effectiveness and have many
shortcomings (for reviews, see Fiore, Becker, & Nero, 1993; Hinshaw, 1994).
Stimulant medications, such as Ritalin, Dexedrine, and Cylert, are the pri
mary treatment for ADD (Hinshaw, 1994; NIMH, 1994; Swanson et al.,
1993). In 9 out of 10 children, these medications help sustain attention and
provide temporary gains in academic productivity (NIMH, 1994), but unfor
tunately, they fail to improve children’s long-term social and academic out
comes (for review, see Hinshaw, 1994). In addition, these medications have
serious side effects. They often suppress appetite and disrupt sleep (Hinshaw,
1994; NIMH, 1994), and in some children, they induce extreme depression
and unusually flattened affect (Douglas, 1972).
56 ENVIRONMENT AND BEHAVIOR / January 2001
Behavioral therapies are a second form of treatment for ADD. These
include direct contingency management, in which children earn or lose
points for specific behaviors, and cognitive behavioral procedures, in which
children learn how to self-monitor attention and impulsive behavior (for
review, see Fiore et al., 1993; Hinshaw, 1994). Unfortunately, these therapies
are typically not sufficient to bring children into normal ranges of functioning
(Fiore et al., 1993; Hinshaw, 1994).
Given the difficulties associated with medication and behavior ther
apy-based treatments, there is a clear need to explore alternative means of
treating ADD. Could contact with nature support the attentional functioning
of children who have ADD? Both theory and evidence regarding the relation
ship between contact with nature and attentional functioning suggest it
NATURE AND ATTENTION
Attention Restoration Theory (Kaplan, 1995) proposes that natural envi-
ronments can assist attentional functioning. To understand how this might be
so, let us review James’s (1892/1962) theory of attention, and then Kaplan’s
(1995) application of that theory to Attention Restoration Theory.
James proposed that humans have two types of attention: voluntary and
involuntary. Voluntary attention, or what Kaplan (1995) calls directed atten-
tion, is the kind of attention we use when we deliberately pay attention. This
form of attention is employed in attending to tasks (e.g., problem solving) or
situations (e.g., driving in heavy traffic) that require sustained attention and
that are not inherently easy to attend to. After prolonged and intense use,
directed attention becomes fatigued (Glosser & Goodglass, 1990; Kaplan,
1995). By contrast, involuntary attention is easy and does not require effort
(James, 1892/1962). James suggested that certain elements in the environ
ment draw on our involuntary attention: “strange things, moving things, wild
animals, bright things, pretty things, words, blows, blood, etc. etc. etc.”
(James, 1892/1962, p. 231). Reliance on involuntary attention can be useful
for the rest and recovery of fatigued directed attention. Kaplan (1995) pro
poses that stimuli and environments that draw primarily on involuntary atten
tion give directed attention a chance to rest. Attention Restoration Theory
suggests that natural environments assist in recovery from directed attention
fatigue in part because they draw on involuntary attention rather than directed
attention (Kaplan, 1995).
A number of studies in adult populations support Attention Restoration
Theory. Several studies have shown that nature draws on involuntary atten
tion (e.g., Kaplan, 1973, 1983; Kaplan & Talbot, 1983; Ulrich, 1981). In
Taylor et al. / COPING WITH ADD 57
addition, a number of other studies have shown that exposure to natural envi
ronments can be effective in restoring directed attention from fatigue (Canin,
1991; Cimprich, 1990; Hartig, Mang, & Evans, 1991; Kuo, in press; Lohr,
Pearson-Mims, & Goodwin, 1996; Miles, Sullivan, & Kuo, 1998; Ovitt, 1996;
Tennessen & Cimprich, 1995). In one study, exposure to natural environ
ments through leisure activities was shown to be related to attentional func
tioning in adults. A study of AIDS caregivers found that nature activities and
quiet activities were associated with robust attentional functioning, whereas
activities such as TV watching, shopping, and watching or playing organized
sports were associated with poorer attentional functioning (Canin, 1991).
NATURE AND ATTENTION IN CHILDREN
Could contact with nature support attention in children? Theoretical and
empirical work in landscape architecture and environmental psychology has
addressed numerous possible other benefits of nature for children, including
providing privacy, mental stimulation, and sensory stimulation and support-
ing important developmental activities such as play, creative forms of play,
and exploratory and divergent thinking (Heseltine, 1987; Jansson, 1984;
Kirkby, 1989; Miller, 1972; Moore, 1986, 1989; Nabhan & Trimble, 1994;
Senda, 1992; Striniste & Moore, 1989; Taylor, Wiley, Kuo, & Sullivan, 1998;
Trancik & Evans, 1995). Only one article has raised the question of nature’s
potential impacts on children’s attention (Trancik & Evans, 1995). Trancik
and Evans (1995) suggest that the design of day care settings should include
spaces supporting “restoration,” such as natural areas, because preschool
children may be susceptible to mental fatigue as they adapt to a new pre
school environment. However, this idea has not been empirically examined.
There are reasons to think that Attention Restoration Theory extends to
children. Like adults, children may become attentionally fatigued. For exam
ple, children’s schoolwork requires extended periods of deliberate, effortful
attention. And like adults, children often must carry out these tasks in a con
text filled with powerful distractions that constantly demand attention,
making it extremely difficult to concentrate on the task at hand. In addition,
because children’s attention is not fully developed (Mackworth, 1976; Shaffer,
1985), they may be fighting off distractions with less attentional control than
adults. Thus, children may need attentionally supportive environments
where they can go to restore. It seems plausible that natural environments
might support attention in children, including children with ADD.
58 ENVIRONMENT AND BEHAVIOR / January 2001
This study examined whether contact with nature assists attentional func
tioning in children with ADD. Two hypotheses were formulated and tested:
one regarding the immediate aftereffects of contact with nature, and the other
regarding the general effects of nature on the severity of a child’s ADD symp
toms. Specifically, we proposed that
Hypothesis 1: Attention deficit symptoms will be more manageable after activities
in green settings than after activities in other settings.
Hypothesis 2: The greener a child’s everyday environment, the more manageable
their attention deficit symptoms will be in general.
To address these hypotheses, we conducted a survey of parents of children
with ADDs. For each child, we collected information about the aftereffects of
leisure activities conducted in different settings, the amount of nature in their
everyday environment, and the severity of their symptoms in general. In addi
tion, six possible alternative explanations for a nature-attention relationship
The questionnaire and procedures for this study were developed through a
multifaceted qualitative data collection effort. The methodology was guided
by interviews with children with ADD, their parents, and a variety of profes-
sionals with expertise in ADD (pediatricians, a professor of special educa-
tion, and a fifth-grade teacher). The methodology was also guided by
classroom observations of four ADD children (10-11 years old).
The questionnaire was pretested with four different families, one family at
a time. As parents completed each section of the questionnaire, the following
concerns were addressed: (a) whether the activities included in the survey
adequately covered the range of activities 7- to 12-year-olds engage in, (b)
whether parents understood the concept of post-activity attentional function
ing, (c) whether the rating scales were appropriate, and (d) whether the nature
measures were easily interpretable and usable. After each pretest, revisions
were made to the questionnaire before further pretesting.
It is worth noting that an effort was made to develop a questionnaire for the
ADD children themselves; however, pretesting indicated that the children
were not able to reliably report on any aftereffects of their activities on their
attention deficit symptoms.
Taylor et al. / COPING WITH ADD 59
The final version of the questionnaire was printed as a small booklet that
took about 30 to 40 minutes to complete. On the cover, the following narra
tive introduced participants to the idea that children’s activities might have
aftereffects on their attention.
Think about how you feel after a difficult week. You may find it more difficult
than usual to pay attention. On the other hand, after a good vacation, you may
find that it’s relatively easy to focus your attention.
We suspect that the same may be true for children. There are many different
ways children can spend their time outside of school. For children with atten
tion deficits, it’s possible that some activities leave children functioning better
than usual, while other activities leave children in worse shape.
In other words, perhaps during the hour or so after your child does a certain
activity, you find that their ADD/ADHD symptoms are worse than usual. Or
vice versa; perhaps after doing another activity, you find that your child is func-
tioning better than usual.
To make the concept attentional functioning more concrete, four specific
attention deficit symptoms were listed:
• Can’t stay focused on unappealing tasks (homework or chores)
• Can’t complete tasks
• Can’t listen and follow directions
• Easily distracted
These symptoms are modified selections from the diagnostic criteria for
Attention Deficit/Hyperactivity Disorder (pp. 83-84 of DSM-IV;APA,
1994). Because Attention Restoration Theory suggests a relationship
between nature and attentional functioning, but not necessarily between
nature and hyperactivity-impulsivity, only symptoms of inattention were
selected. In addition, because parents rarely observe their children in the
classroom, only symptoms readily apparent in a home setting were
In the first section of the questionnaire, participants were asked to nomi
nate up to two afterschool and weekend activities that they felt left their
child functioning especially well and up to two activities that they felt left
their child functioning especially poorly. Parents completed the sentence,
“After ____ my child’s ADD symptoms are much less noticeable than usual.
My child is in good shape.” Parents were asked to nominate up to two best
activities. Parents then did the same for worst activities: “After ____ my
60 ENVIRONMENT AND BEHAVIOR / January 2001
child’s ADD symptoms are much more noticeable than usual. My child is in
bad shape.” For both items, parents had the option of marking none, if they
had not noticed any activities that were particularly helpful or harmful for
their child’s attention. About 66% of parents were able to nominate at least
one activity that was best for their child; 68% were able to nominate at least
one that was worst. Parents’ nominations were later coded in terms of their
likely settings by an individual blind to the best and worst labels. Each of the
activities was classified as either Green (likely to take place in a relatively
natural setting), Not Green (unlikely to take place in a relatively natural set
ting), or Ambiguous (ambiguous with respect to physical setting). For exam
ple, camping trip, fishing, and soccer were coded as Green, whereas video
games, TV, and homework were coded as Not Green. Activities such as play
ing outside and rollerblading were coded as Ambiguous.
In the second section, participants were presented with a list of afterschool
and weekend activities and asked to rate each activity in terms of any afteref
fects of that activity on their child’s attention deficit symptoms. These
postactivity attentional functioning ratings, or PAAF ratings, were made on a
5-point Likert-type scale from 1 = much worse to5=much better, with a mid-
point of 3 = same as usual; don’t know was also an option. Twenty-five activi-
ties were presented in three lists: 11 activities conducted indoors, 6 activities
conducted in built outdoor spaces (defined as mostly human-made areas—
parking lots, downtown areas, or just a neighborhood space that doesn’t have
much greenery), and 8 activities conducted in green outdoor spaces (defined
as mostly natural areas—a park, a farm, or just a “green” backyard or neigh-
borhood space). Each activity was rated for two social contexts: after the
activity was conducted alone, or with one person, and after the activity was
conducted with two or more people.
In the final section of the questionnaire, parents answered a series of gen
eral questions about their child, their household, and the child’s everyday sur
roundings. Parents answered the question, In general, how severe would you
say your child’s ADD or ADHD symptoms are (when not on medication)?
using a 5-point Likert-type scale, from 1 = very mild to5=very severe. They
reported their child’s age, sex, grade in school, diagnoses other than ADD/
ADHD, number of adult caregivers, and the household income. In addition,
parents assessed the greenness of their child’s everyday surroundings.
To assist parents in assessing the level of nature in their child’s everyday
surroundings, parents were first presented with a set of six photo pairs of pos
sible play settings ranging from places indoors where it feels very much
indoors (two photos of windowless rooms) to places where there might be
“wild” things: flowers, trees, animals, etc. (two photos of relatively untamed
landscapes). The photo pairs were independently rated by 21 horticulture
Taylor et al. / COPING WITH ADD 61
students for greenness or naturalness on a scale of1=lowto10=high), with
an interrater reliability of .994. To avoid collecting information about play
spaces used during other seasons (e.g., winter), parents were asked to select
one photo pair description as representative of where their child played dur
ing the previous week. Parents were then asked whether their child’s activi
ties in the previous week were representative of their normal routine (yes/no).
In addition to assessing the level of nature in their child’s typical play set
tings, parents were asked to assess the overall greenness of their family’s resi
dence, the amount of tree cover in their yard, and the amount of grass in their
yard. Overall greenness around the home was rated on a 5-point Likert-type
scale (1 = not at all green,5=very green). To assess tree cover, parents were
shown four photos depicting yards with different levels of tree cover and
asked to select one that best represented the amount of tree cover in their front
yard and one that best represented the amount of tree cover in their back yard.
The amount of grass was measured through the same procedure.
PARTICIPANTS AND PROCEDURE
Participation was limited to parents or legal guardians of children 7 to 12
years old who had been formally diagnosed with ADD or ADHD (i.e., diag-
nosed by a physician, psychologist, or psychiatrist).
Participants were recruited through flyers distributed to pediatricians’
offices, medical clinics, schools, and parent support groups such as Children
and Adults with Attention Deficit/ Hyperactivity Disorder (CHADD). Partic-
ipants were also recruited through advertisements placed in major newspa-
pers. Newspaper advertisements were restricted to the midwestern United
States to ensure roughly comparable climate and vegetation across the sam
ple. The flyers and advertisements invited parents to participate in a
mail-back or Internet-based survey about the effects of ADD/ADHD chil
dren’s afterschool and weekend activities on their symptoms. Two incentives
were offered: a list of recommendations based on the study’s findings and a
choice of a pizzeria gift certificate or a children’s book about ADD.
Questionnaire data were collected, as suggested by a pediatrician and spe
cial education professor, when the attentional demands of school would make
potential effects of nature on attention most salient to parents. Data were
collected from mid-September, after children’s school routines were well
established, through the end of October, before inclement weather might sig
nificantly limit outdoor play. Paper copies of the questionnaire were mailed
to parents who volunteered by phone or by e-mail, and an electronic version
of the questionnaire was also made available on the Internet. The Dillman
(1978) follow-up methodology was employed to encourage participants to
62 ENVIRONMENT AND BEHAVIOR / January 2001
return the mail-back questionnaire within the time frame of the study. By the
deadline, 77 paper copies of the questionnaire were returned, or 58% of those
mailed. An additional 19 questionnaires were completed on the Internet, for a
total of 96 completed questionnaires.
Given the use of convenience sampling, it is important to note that this
sample was similar to other samples of children with ADDs. The ratio of boys
to girls with attention deficits in the general population is estimated to be 3:1
(Barkley, 1990; Bender, 1997) or even 4:1 (American Psychiatric Associa
tion, 1994); the ratio of boys to girls in this sample was 3:1. Overall, this sam
ple had more children with ADHD (61%) than ADD (39%). The ratio of
ADD to ADHD in the general population is estimated at 1:1.7 for boys and
1:2.2 for girls (Szatmari, Offord, & Boyle, 1989); the ratio of ADD to ADHD
in this sample was 1:1.6 for boys and 1:1.5 for girls. The percentage of ADD
or ADHD boys having at least one comorbid disorder in the general popula
tion is 44%, whereas 29% of girls have at least one comorbid disorder
(Szatmari et al., 1989); in our sample, 52% of boys had one comorbid disor-
der, and 36% of girls had one comorbid disorder. The mean age of children in
this sample was 9.4 years, with a standard deviation of 1.5 years. About 63%
of the parents reported their household income to be $50,000 or greater.
After the questionnaire data from the complete sample were analyzed, a
subset of questionnaire participants was invited to a focus group dinner to
discuss the findings. Eight questionnaire participants who had indicated
interest in a follow-up interview attended. Focus group participants first
briefly reacquainted themselves with the questionnaire and were asked to
discuss any parts of the questionnaire they had found difficult to understand
or complete. They were then asked if they had any guesses about the central
hypothesis of the study, or “what the study was after.” Some of the major find
ings were then presented, and participants were asked to describe any experi
ences they had had related to each of these findings, either in keeping with the
findings or in contrast to the findings. Finally, participants were asked to
describe their observations regarding different activities, different activity
settings, and their aftereffects on their children’s symptoms
Does contact with nature assist attentional functioning in children with
ADD? First, we present tests of the central hypotheses, along with relevant
quotes and anecdotes from interviews with parents. Then, we present tests of
several alternative explanations for the central findings.
Taylor et al. / COPING WITH ADD 63
TESTING OF CENTRAL HYPOTHESES
Each of the two central hypotheses was tested in multiple ways. Tests of
the first hypothesis involved within subjects comparisons; tests of the second
hypothesis involved between subjects comparisons.
Hypothesis 1. The first hypothesis was that attention deficit symptoms
will be more manageable after activities in green settings than after activities
in other settings. This hypothesis was first tested by examining the activities
nominated by parents as particularly helpful (best) or harmful (worst) for
their children’s attention deficit symptoms: 113 best activities and 106 worst
activities were nominated. If green settings are more attentionally support-
ive, then activities typically conducted in green settings should be
overrepresented among the activities nominated as best and
underrepresented among the activities nominated as worst. Indeed, as Table 1
shows, of the 20 Green activities (activities judged by an independent coder
as likely to take place in a relatively natural setting), 17 were nominated as
best, and 3 were nominated as worst (85% vs. 15%). Furthermore, Not Green
activities were overrepresented among the activities nominated as worst
(57%; 43% best). A chi-square confirmed that the likelihood that an activity
would be nominated as best or worst significantly differed for different set
(2) = 12.74, p < .01. This finding raises the possibility that partici
pants nominated Green activities as best because they had guessed the central
hypothesis of the study. However, during the focus group, questionnaire par
ticipants said they had not guessed that the study was about the relationship
between nature and attention.
The first hypothesis was then tested by examining parents’ ratings of their
children’s attention deficit symptoms after participating in various activities
in one of three settings. The mean PAAF rating for all activities was 3.22
(between 3 = same as usual and4=better than usual) with a standard devia
tion of .48. Mean PAAF ratings for specific activities ranged from 2.14, for
homework with others indoors, to 3.80, for riding bike alone in green set-
64 ENVIRONMENT AND BEHAVIOR / January 2001
Activities Nominated as Best and Worst for
Attention Deficit Disorder Symptoms, Classified by Likely Setting
Likely Setting Best Worst
Green (e.g., fishing, soccer) 85% (17) 15% (3)
Ambiguous (rollerblading, playing outside) 56% (43) 44% (34)
Not Green (video games, TV) 43% (53) 57% (69)
NOTE: Numbers in parentheses are
s for each group.
tings. If nature is supportive of ADD children’s attentional functioning,
activities conducted in green outdoor settings should receive higher PAAF
ratings, on average, than activities conducted in indoor settings or built out-
door settings. In fact, a repeated measures ANOVA indicates that PAAF rat-
ings do differ by setting, F(2, 82) = 15.51, p < .0001 (see Figure 1). Green
activities received a significantly higher PAAF rating on average than indoor
activities, Fishers PLSD d = .30, p < .0001, (M = 3.53 versus 3.22, respec-
tively) and a significantly higher rating than built outdoor activities, Fishers
PLSD d = .28, p < .0001, (M = 3.53 versus 3.24, respectively).
In the comparison of PAAF ratings for indoor versus green outdoor set
tings reported above, homework was included as one of the indoor activities
because it constitutes an important afterschool and weekend indoor activity.
However, whereas the other activities rated in the survey are truly leisure
activities, homework is not a leisure activity, and is particularly attentionally
demanding. Thus, it seems unfair to compare indoor activities to outdoor
activities with homework included as an indoor activity. Hence, we com
pared PAAF ratings for indoor versus green outdoor activities, excluding
homework from the analysis. Even with homework excluded, the pattern
held, with green outdoor activities still receiving significantly greater PAAF
scores than indoor activities, Fisher’s PLSD d = .25, p = .0001.
The aftereffects of activities on children’s attention deficit symptoms
were further explored in the focus group. Participants were asked if they had
had any experiences, either positive or negative, related to any aftereffects of
green settings on their child’s attention. One parent said she had recently
begun taking her son to the local park for 30 minutes each morning before
Taylor et al. / COPING WITH ADD 65
Figure 1: Mean Postactivity Attentional Functioning Ratings for Indoor, Built
Outdoor, and Green Outdoor Activities
school because the weather was nice, and they “had some time to kill.” She
Come to think of it, I have noticed his attitude toward going to school has been
better, and his school work has been better this past week. I think it’s because
spending time at the park is pleasurable, peaceful, quiet, calming.
Another parent suggested that his son, although usually struggling against his
attention deficit symptoms, can “hit golf balls with me for 2 hours at a time,”
and “he fishes for hours at a time alone.” This father reported that, after these
activities, his son’s attention deficit symptoms “are minimal,” and “he’s very
relaxed.” “When I read the results of your study, they hit me in the face,” con
tinued this parent. “I thought, yes I’ve seen this!” (referring to the positive
effects of nature on ADD children’s attentional functioning). In contrast,
none of the focus group participants could report any instances in which
green outdoor activities exacerbated their child’s attention deficit symptoms.
Hypothesis 2. The second central hypothesis in this study was that the
greener the child’s everyday environment, the more manageable their atten-
tion deficit symptoms will be in general. This hypothesis was first tested by
examining the relationship between the greenness of the child’s play setting
during the previous week and the severity of their attention deficit symptoms.
The mean rating of children’s overall severity of symptoms fell between
average and severe (M = 3.53, range = 1-5). Many (39%) were rated as having
average severity of symptoms, whereas half (50%) had symptoms that were
rated as severe or very severe. Most parents reported that their children
played in places with big trees and grass (44%), or indoor places without win
dows (16%), or places where there is a lot of open grass (13%). If greenness
of play environment affects attentional functioning, then children who play
in greener settings should receive lower severity of symptoms ratings.
Indeed, a regression analysis between horticulture students’ greenness rat
ings of the play setting categories and parents’ severity of symptoms ratings
revealed a significant positive relationship, R
= .08, F(1, 91) = 8.18, p < .01.
The greener the child’s play environment during the previous week, the less
severe their symptoms.
Does this relationship hold when children were excluded from the analy
ses if their play environments during the previous week was atypical of their
usual play environments? Yes, the relationship still held; R
= .06, F(1, 70) =
4.48, p < .05.
To further explore this relationship, Figure 2 shows the mean severity of
ADD symptoms associated with different play settings, excluding the built
66 ENVIRONMENT AND BEHAVIOR / January 2001
outdoors setting due to the few children in that category. The pattern of means
reinforces the regression findings. In addition, the pattern of means raises the
intriguing possibility that indoor settings with windows may be more sup-
portive than indoor settings without windows and that there are minimal dif-
ferences between open grassy settings and settings that include trees.
This hypothesis was also examined by testing for a relationship between
various measures of residential greenness and the overall severity of symp
toms. Most children’s residential surroundings (overall greenness) were
rated as being quite green (M = 4.26, on a 5-point scale). Most children had a
large area of grass in their front yard and in their back yard (M = 2.91 and
3.27, respectively, ona1to4-point scale). Children also had large amounts of
tree cover in front and in back of their homes (M = 2.92 and 3.15, respectively,
on a 4-point scale). Based on our second hypothesis, children who live in resi
dential areas rated as highly green should receive lower overall severity of
symptoms ratings than children who live in less green residential settings.
However, we did not find this to be the case; regression analyses indicate that
measures of overall greenness, grass cover, and tree cover in the front and
back yards were not significantly related to severity of symptoms.
Given that three measures of nature were found to be related to attention,
why didn’t we find a relationship between residential nature and severity of
Taylor et al. / COPING WITH ADD 67
Figure 2: Mean Severity of Attention Deficit Symptoms for Five Play Settings
symptoms? One possible explanation is that the children in this sample do not
gain much exposure to the nature surrounding their homes. It is plausible that
these children do not spend much time in their yards, especially because there
was such a clear, significant relationship between the greenness of where
they played and the severity of their symptoms. The fact that most of the sam
ple (75%) were boys may explain the nonsignificant relationship between
residential nature and these children’s attentional functioning (severity of
symptoms). Interviews with parents during pretesting, as well as comments
from the focus group, indicate that boys rarely play in their own yards; they
generally choose to play elsewhere.
The effects of extended contact with nature on overall severity of symp
toms were further explored in the focus group. Parents were asked, “Has any
one taken your ADD child on a ‘pure’ nature experience, such as camping, hik
ing, fishing, biking, etc. in a State park, National park, or other natural area? If
so, what happened? Anything memorable?” One parent’s response was “Pure
nature vacations are the only vacations we can take! Theme parks are a night-
mare. Two weeks camping in a pop-up camper is just bliss. We have a great
time. He’s great.”
TESTING OF ALTERNATIVE EXPLANATIONS
The findings above indicate that there is a relationship between nature and
attentional functioning in children with ADD. This is consistent with
Kaplan’s theory that contact with nature leads to attentional restoration.
Might it be, however, that the correlations reported above were obtained in
the absence of any real relationship between nature and attentional function
ing? In other words, does the nature-attention relationship exist merely
because both nature activities and attentional functioning are related to some
other, third, factor? In search of a potential third factor, six alternative hypoth
eses are considered below.
First, could it be that green activities enhance attentional functioning not
because they are green, but because they are conducted outdoors? If so, we
would expect that green outdoor activities and built outdoor activities to have
average PAAF scores that would not differ significantly. However, a paired t
test examining differences in PAAF scores between green outdoor activities
and built outdoor activities indicates that green activities received signifi
cantly higher average PAAF scores than built outdoor activities, t(82) = 4.38,
p < .0001 (M = 3.54 versus 3.24, respectively). Not only did built outdoor
activities receive lower PAAF scores than green outdoor activities, but a
paired t test indicates that built outdoor activities’ PAAF scores are not signif
icantly greater than indoor activities’ PAAF scores, t(82)= .29, p = .77, (M =
68 ENVIRONMENT AND BEHAVIOR / January 2001
3.24 and 3.24, respectively). Thus, green activities’ relationship to attention
cannot be explained by green activities taking place outdoors.
Second, could it be that green activities enhance attentional functioning
not because they are green but because they are conducted in a particular
social context, either alone or with one person, or with larger groups? If so,
we would expect that when social context is controlled, the physical environ
ment in which an activity takes place would have no effect on attention deficit
symptoms. A 2 × 2 (2 physical settings × 2 social contexts) repeated measures
ANOVA indicates that green outdoor activities received higher PAAF scores,
on average, than did indoor activities, F(1, 85) = 44.69, p < .0001, or built out
door activities, F(1, 72) = 13.04, p < .01. Furthermore, no interaction was
found between physical setting and social setting in either of these analyses.
Thus, the social environment cannot explain the relationship between PAAF
scores and green settings.
Third, could it be that green activities enhance attentional functioning not
because they are green, but because they are physically active? If so, we
would expect that physically active green outdoor activities would receive
higher PAAF scores than passive green activities. To examine this possibility,
an independent coder coded all the activities as active or passive. For exam-
ple, reading books or magazines and creative activities were coded as pas-
sive, whereas bike, skate or skateboard, explore, climb tree, or play in tree
houses were coded as active. A paired t test indicates no significant difference
between PAAF scores of active and passive activities done in green settings,
t(83) = 1.13, p = .26. Thus, green activities’ relationship to attention cannot
be explained by green activities being either active or passive.
Fourth, could it be that green activities enhance attentional functioning
not because they are green, but because these activities are qualitatively dif
ferent from activities done in other settings? Could it be that the activities we
selected to measure PAAF for green outdoor settings happen to be uniquely
supportive of attentional functioning whereas the activities selected for the
indoor and built outdoor settings are uniquely unsupportive of attentional
functioning, thus making the differences found not due to setting but due to
the activities themselves. If so, we would expect that we would not find set
ting differences when comparing PAAF ratings for a single set of activities
after a child does the activities in each of the three settings. The activities
matched across setting were creative activities (art, music, models, Legos,
collections, etc.), pretending (house, action figures, Power Rangers, etc.),
and organized sports. A repeated measures ANOVA comparing three differ
ent physical settings and controlling for two social settings indicates that
attentional functioning differs systematically by physical setting, F(2, 62) =
3.06, p = .05. Moreover, paired comparisons indicated that the same
Taylor et al. / COPING WITH ADD 69
activities, when conducted in green outdoor settings, were associated with
better attentional functioning than when they were conducted in either built
outdoor settings or indoor settings, F(1, 63) = 6.17, p < .05, and F(1, 81) =
4.14, p = .05, respectively). Thus, the differences in attentional functioning
between green activities and activities conducted in other settings seem to be
due to setting rather than activity.
Fifth, could it be that green activities enhance attentional functioning not
because they are green but because they are preferred? If this is the case, then
preferred activities should be attentionally supportive. Consistent with this
idea, attentionally supportive activities were indeed preferred; a t test indi
cated that the mean preference rating for activities nominated as attentionally
best for ADD children was significantly greater than 3.0 (a neutral preference
rating), t(62) = 29.70, p < .0001 (M = 4.70). However, preferred activities
were also nominated as attentionally worst for ADD children, t(64) = 3.03,
p < .01 (M = 3.45). Thus, worst activities were preferred as well as best activi
ties. Both means are more positive than neutral. Thus, preference does not
appear to be responsible for making an activity attentionally supportive, and
the relationship between green activities and attention cannot be explained
by green activities being preferred.
Finally, could it be that some activities are more supportive of attentional
functioning because they coincide with medicated periods? Although our
data do not permit a direct test of this possibility, we can test for a relationship
between medication effects and activities nominated as best and worst. If medi-
cation effects are related to activities being nominated as attentionally sup-
portive, then we would expect best activities to have been conducted while a
child was medicated and worst activities to have been conducted while a child
was unmedicated. However, parents’ reports indicate that most activities
(64%) nominated as best occur while medications are no longer effective (the
dose has worn off). Conversely, 54% of activities nominated as worst occur
while medications are still effective. Thus, the relationship between green
activities and attention cannot be explained by green activities coinciding
with medicated periods.
These analyses indicate that of the six alternative explanations tested, none
could explain the nature-attention relationship found.
Does nature support attentional functioning in children with ADDs? Sev
eral analyses suggest that contact with nature is systematically related to less-
70 ENVIRONMENT AND BEHAVIOR / January 2001
ened attention deficit symptoms. Activities nominated as helpful in reducing
attention deficit symptoms were disproportionately likely to take place in
green outdoor settings. Conversely, activities nominated as exacerbating
symptoms were disproportionately likely to take place in non-green outdoor
settings. Parent ratings of PAAF were also systematically higher, on average,
for activities conducted in green outdoor settings than for activities con
ducted in either built outdoor or indoor settings. Although the greenness of a
child’s residential setting was unrelated to the severity of their ADD symp
toms, the greenness of their play setting was related to symptom severity;
ADD symptoms were milder for those children with greener play settings.
Children who played in windowless indoor settings had significantly more
severe symptoms than children who played in grassy outdoor spaces with or
without trees did.
Multiple alternative explanations for these findings were tested. The rela
tionship between nature and attention could not be explained by confounds
between contact with nature and any of the following factors: being outdoors,
social environment, amount of physical activity, types of activity, preference
for nature, or timing of medication.
Although these findings are based on correlational data, the design of this
study provides more support for a causal interpretation than is typical for
correlational work. First, most correlational work gives no confidence in the
temporal order of the relationship found, establishing only that A is related to
B. This study not only establishes a strong nature-attention relationship, it
also suggests a direction to that relationship. Because this study specifically
focuses on attentional functioning after activities, it seems more plausible
that participation in green activities causes improved attentional functioning
than that improved attentional functioning causes participation in green
activities. Remember that parents had the option of indicating that their
child’s attentional functioning was the same as usual, if indeed the child did
not improve after the activities. Second, most correlational work involves
between-subjects comparisons, in which individual differences may account
for the findings. This study establishes a strong nature-attention relationship
within subjects. We found that green activities are associated with better
attentional functioning within the same individual. Such within-individual
fluctuations in attentional functioning cannot be accounted for by
between-individual differences such as intelligence or wealth. Moreover, the
combination of between- and within-subjects comparisons in this study over
comes the limitations of a within-subjects comparison alone. For example,
parents might rate their child as functioning better attentionally after activi
ties in green settings simply because they believe spending time in green set
tings is good for children. This would explain the within-subjects findings
Taylor et al. / COPING WITH ADD 71
but not the between-subjects findings. Thus, although definitive evidence of a
causal relationship awaits a true experiment, we believe the current findings
strongly merit a causal interpretation.
Before we discuss the contributions and implications of these findings, a
few cautions regarding their generalizability are in order. The sample used
here, although relatively representative of the general population of ADD
children, does have some potential limitations. The children in this sample
were perceived by their parents to have relatively severe attention deficit
symptoms. Also, the families were relatively wealthy, with 63% earning an
annual household income of $50,000 or more. And the majority of this sam
ple lived in relatively green residential areas. Thus, the findings may not gen
eralize to children with milder symptoms, who have families with lower
incomes, or who live in relatively barren residential surroundings.
In addition, the location and timing of the data collection may pose some
limitations regarding generalizability. The data were collected from a limited
geographic region, the midwestern United States. Thus, the question arises,
do these findings apply to children living in regions without green trees and
grass? For example, children in desert settings may not receive the same ben-
efits from contact with nearby natural outdoor settings. Furthermore, this
study was conducted within a short period of time during a single season,
autumn. Is the nature-attention relationship still as strong during the summer
months, when children have fewer attentional demands (i.e., no school-
work)? Is the nature-attention relationship as strong during the winter
months, when there is very little green vegetation available?
This work contributes to the research on nature and attention in three
ways. The work here extends Attention Restoration Theory, expands the lit
erature concerning children and nature, and provides a potential new method
ology for studying directed attention in children.
This study extends Attention Restoration Theory to a new population, pro
viding evidence that the theory may apply to children. Whereas Attention
Restoration Theory suggests that nature supports directed attention function
ing in all humans, previous research has only provided evidence that the the
ory applies to adults (Canin, 1991; Cimprich, 1990; Hartig et al., 1991; Kuo,
in press; Lohr et al., 1996; Miles et al., 1998; Tennessen & Cimprich, 1995).
This study is the first to indicate that the theory applies to at least a subpopu-
72 ENVIRONMENT AND BEHAVIOR / January 2001
lation of children, children with ADD. Thus, there is now evidence that
Attention Restoration Theory applies to both adults with normal attentional
functioning and children whose attentional functioning is compromised.
Together, these findings provide some indication that the nature-attention
relationship may apply to all children.
This study also extends the literature on the benefits of nature for children.
The previous literature has provided some evidence that green spaces foster
play and—of particular importance—creative play (Kirkby, 1989; Moore, 1989;
Taylor et al., 1998). In addition, previous investigators have suggested that
contact with nature supports children’s general well-being by providing chil
dren with privacy and mental and sensory stimulation (Heseltine, 1987; Jansson,
1984; Miller, 1972; Nabhan & Trimble, 1994; Senda, 1992; Striniste & Moore,
1989). To date, however, no studies have examined the effects of contact with
nature on children’s attentional functioning. Trancik and Evans (1995) did
speculate that, for preschoolers, the stress of the new school environment
might cause attentional fatigue and that, therefore, preschoolers might bene-
fit from opportunities to play in green settings. The findings here suggest that
Trancik and Evans’s ideas are worth testing.
Finally, this study provides a potential new methodology for studying
directed attention in children. The consistent and statistically significant dif-
ferences between different activities found here suggest that parents are able
to systematically assess the aftereffects of activities on their children’s
attentional functioning and can estimate the magnitude of these effects on a
Likert-type scale. Furthermore, it appears that most parents are able to nomi-
nate activities that have especially positive and negative effects on their
child’s attention. Future research should assess the reliability and concurrent
validity of these measures.
IMPLICATIONS FOR PRACTICE AND FUTURE RESEARCH
The findings here have a number of implications for practice and future
research. For children with ADD and their parents, these findings have a clear
and inexpensive implication: Children with ADD can support their
attentional functioning and minimize their symptoms simply by spending
time in green settings. More specifically, children with ADD might use these
findings in the following ways. First, before engaging in attentionally
demanding tasks such as schoolwork and homework, ADD children might
maximize their attentional capacity by spending time in green settings. Sec
ond, ADD children might reduce the overall severity of their symptoms by
spending time in green settings on a daily basis. According to parents in the
focus group, children with ADD who engage in green activities function
Taylor et al. / COPING WITH ADD 73
better both during the activity and for some time afterward. It is worth noting
that children with ADD can follow these recommendations at little or no
financial cost by using public and private green areas.
The findings of this study have implications for the design of children’s
environments such as school yards. Given that maximal attentional function
ing is necessary for optimal academic performance, one implication of these
findings is that green schoolyards could play an important role in children’s
academic pursuits. For example, recess may be more than just a time for
releasing physical energy but also an important time for restoring attention.
Children with ADD, and possibly all children, may perform better through
out the school day if given breaks in a green environment. In addition, per
haps something as simple as a view out the classroom window onto a green
space may be providing children with much needed rest of their directed
The findings of this study also have a number of implications for future
research. Future research might replicate these findings both in similar set-
tings (children’s afterschool and weekend play environments), with other
populations (e.g., ADD children in the southwest United States, non-ADD
children), and in other settings. For example, do children who attend schools
with particularly green school yards function better attentionally throughout
the day than children who attend less green schools? Does the physical set-
ting of summer camp affect ADD children’s attention deficit symptoms? Per-
haps, summer camps in natural settings (e.g., camping in a state park) are
more beneficial for children with ADD than indoor summer camps (e.g.,
indoor sports camps or arts camps). Furthermore, future research might
explore which specific elements of green settings are crucial in supporting
Future research might also explore the temporal characteristics of the
nature-attention relationship. In this study, we examined functioning imme
diately after participation in green activities but did not measure the duration
of the activities or the duration of the effects. Is it necessary to spend some
minimum amount of time in nature-related activities to experience the restor
ative benefits of nature? For children with ADD, how does a 10-minute walk
in the park compare to a 30-minute walk in the park in terms of restoring
attentional functioning? Kuo (in press) has proposed that future research
should determine the shape of the dose response curve for nature and atten
tion. For example, perhaps attentional functioning increases with increasing
exposure to nature only up to a point, after which the benefits level out and
additional exposure to nature produces little additional benefit. Another issue
that deserves investigation concerns the duration of the effects. How long do
74 ENVIRONMENT AND BEHAVIOR / January 2001
they last? Do the effects degrade in a linear fashion or do they degrade
This study has shown that nature may support attentional functioning in
children with ADD. These finding have tremendous implications for a large
number of children (more than 2 million in the United States alone) strug
gling day-in and day-out with attention deficit symptoms. These children and
their families could potentially benefit from something as simple as spending
time in green areas. In addition, these findings hold potential value for chil
dren who do not have ADD. Optimal levels of attentional functioning are
essential for all children so that they maximize learning and achievement in
school. Thus, all children’s attentional functioning may benefit from some
thing as inexpensive and direct as incorporating vegetation into places where
children live, learn, and play.
1. The acronym ADD will be used throughout this article because this research theoretically
hinges on children’s attention deficits. However, the information also applies to ADHD, as
ADHD is a broader diagnostic term under which a child can be diagnosed as predominantly inat-
tentive (attention deficit), or inattentive and hyperactive/impulsive (American Psychiatric Asso-
2. It is striking that in spite of a small n and thus low power for analysis, girls’ severity of
symptoms were significantly related to several measures of residential greenness.
Alessandri, S. M. (1992). Attention, play, and social behavior in ADHD preschoolers. Journal of
Abnormal Child Psychology, 20(3), 263-288.
American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disor
ders (4th ed.). Washington, DC: American Psychiatric Press.
Barkley, R. A. (1990). Attention Deficit Hyperactivity Disorder: A handbook for diagnosis and
treatment. New York: Guilford.
Barkley, R. A. (1995). Taking Charge of ADHD. New York: Guilford.
Barkley, R. A. (1997). Behavioral inhibition, sustained attention, and executive functions: Con
structing a unifying theory of ADHD. Psychological Bulletin, 121(1), 65-94.
Barkley, R. A. (1998, September). ADHD in children and adolescents: Theory, diagnosis, and
management. Paper presented at the Developing Child XIX Conference, Champaign, IL.
Barkley, R. A., Anastopoulos, A. D., Guevremont, D. C., & Fletcher, K. E. (1992). Adolescents
with Attention Deficit Hyperactivity Disorder: Mother-adolescent interactions, family
Taylor et al. / COPING WITH ADD 75
beliefs and conflicts, and maternal psychopathology. Journal of Abnormal Child Psychol
ogy, 20(3), 263-288.
Bender, W. N. (1997). Understanding ADHD: A practical guide for teachers and parents. Upper
Saddle River, NJ: Prentice Hall.
Berk, L. E. (1994). Child development (3rd ed.). Boston: Allyn & Bacon.
Canin, L. H. (1991). Psychological restoration among AIDS caregivers: Maintaining self-care.
Unpublished dissertation, University of Michigan, Ann Arbor.
Cimprich, B. (1990). Attentional fatigue and restoration in individuals with cancer. Unpub
lished dissertation, University of Michigan, Ann Arbor.
Dillman, D. A. (1978). Mail and telephone surveys: The total design method. New York: John
Douglas, V. I. (1972). Stop, look, and listen: The problem of sustained attention and impulse
control in hyperactive and normal children. Canadian Journal of Behavioral Science, 4(4),
Fiore, T. A., Becker, E. A., & Nero, R. C. (1993). Interventions for students with attention defi
cits. Exceptional Children, 60(2), 163-173.
Foster, J. K., Eskes, G. A., & Stuss, D. T. (1994). The cognitive neuropsychology of attention: A
frontal lobe perspective. Cognitive Neuropsychology, 11(2), 133-147.
Glosser, G., & Goodglass, H. (1990). Disorders in executive control functions among aphasic
and other brain damaged patients. Journal of Clinical and Experimental Neuropsychology,
Hartig, T., Mang, M., & Evans, G. W. (1991). Restorative effects of natural environment experi-
ences. Environment & Behavior, 23(1), 3-26.
Heseltine, P. a. J. H. (1987). Playgrounds: The planning, design, and construction of play envi-
ronments. London: Mitchell.
Hinshaw, S. P. (1994). Attention deficits and hyperactivity in children (Vol. 29). Thousand Oaks,
Hynd, G. W., Semrud-Clikeman, M., Lorys, A. R., Novey, E. S., & Eliopulos, D. (1990). Brain
morphology in developmental dyslexia and attention deficit disorder/hyperactivity. Archives
of Neurology, 47, 919-926.
James, W. (1962). Psychology: The briefer course. New York: Collier Books. (Original work
Jansson, B. (1984). Children’s play and nature in an urban environment. New York: Peter Lang.
Kaplan, R. (1983). The role of nature in the urban context. In I. Altman & J. Wohlwill (Eds.),
Behavior and The natural environment (pp. 127-161). New York: Plenum.
Kaplan, R. (1973). Some psychological benefits of gardening. Environment & Behavior, 5(2),
Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. Journal
of Environmental Psychology, 15, 169-182.
Kaplan, S., & Talbot, J. F. (1983) Psychological benefits of a wilderness experience. Human
Behavior & Environment: Advances in Theory & Research, 6, 163-203.
Kirkby, M. (1989). Nature as refuge in children’s environments. Children’s Environment Quar
terly, 6(1, spring), 7-12.
Kuo, F. E. (in press). Effective life functioning in the inner city: Impacts of environment and
attention. Environment & Behavior.
Lohr, V., Pearson-Mims, C., & Goodwin, G. (1996). Interior plants may improve worker produc
tivity and reduce stress in a windowless environment. Journal of Environmental Horticul
ture, 14(2), 97-100.
76 ENVIRONMENT AND BEHAVIOR / January 2001
Mackworth, J. F. (1976). Development of attention. In V. Hamilton & M. Vernon (Eds.), The
development of cognitive process (pp. 111-152). London: Academic Press.
Miles, I., Sullivan, W., & Kuo, F. (1998). Ecological restoration volunteers: The benefits of par
ticipation. Urban Ecosystems, 2, 27-41.
Miller, P. L. (1972). Creative outdoor play areas. Englewood Cliffs, NJ: Prentice Hall.
Moore, R. C. (1986). The power of nature orientations of girls and boys toward biotic and abiotic
play settings on a reconstructed schoolyard. Children’s Environments Quarterly, 3(3),
Moore, R. C. (1989). Plants as play props. Children’s Environments Quarterly, 6(1), 3-6.
Nabhan, G. P., & Trimble, S. (1994). The geography of childhood: Why children need wild
places. Boston: Beacon.
National Institute of Mental Health. (1994). Attention Deficit Hyperactivity Disorder (No.
94-3572). Washington, DC: Author.
Ovitt, M. (1996). The effect of a view of nature on performance and stress reduction of ICU
nurses. Unpublished master’s thesis, University of Illinois, Urbana-Champaign.
Senda, M. (1992). Design of children’s play environments. New York: McGraw-Hill.
Shaffer, D. R. (1985). Developmental psychology: Theory, research, and applications.
Monterey, CA: Brooks/Cole.
Shue, K. L., & Douglas, V. I. (1992). Attention Deficit Hyperactivity Disorder and the frontal
lobe syndrome. Brain and Cognition, 20, 104-124.
Striniste, N. A., & Moore, R. C. (1989). Early childhood outdoors: A literature review related to
the design of childcare environments. Children’s Environments Quarterly, 6(4), 25-31.
Swanson, J., McBurnett, K., Wigal, T., Pfiffner, L. J., Lerner, M. C., WIlliams, L., Christian, D.
L., Tamm, L., Willcutt, E., Crowley, K., Clevenger, W., Khouzam, N., Woo, C., Crinella, F.
M., & Fisher, T. D. (1993). Effect of stimulant medication on children with Attention Deficit
Disorder: A review of reviews. Exceptional Children, 60(2), 154-162.
Szatmari, P., Offord, D. R., & Boyle, M. H. (1989). Ontario Child Health Study: Prevalence of
attention deficit disorder with hyperactivity. Journal Child Psychology and Psychiatry, 30,
Taylor, A. F., Wiley, A., Kuo, F. E., & Sullivan, W. C. (1998). Growing up in the inner city: Green
spaces as places to grow. Environment & Behavior, 30(1), 3-27.
Tennessen, C. M., & Cimprich, B. (1995). Views to nature: Effects on attention. Journal of Envi
ronmental Psychology, 15(1), 77-85.
Trancik, A. M., & Evans, G. W. (1995). Spaces fit for children: Competency in design of daycare
center environments. Children’s Environments, 12(3), 311-319.
Ulrich, R. S. (1981). Natural versus urban scenes: Some psychophysiological effects. Environ
ment & Behavior, 13(5), 523-556.
Taylor et al. / COPING WITH ADD 77