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Happy to help? A systematic review and meta-analysis of the effects of performing acts of kindness on the well-being of the actor


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Do acts of kindness improve the well-being of the actor? Recent advances in the behavioural sciences have provided a number of explanations of human social, cooperative and altruistic behaviour. These theories predict that people will be ‘happy to help’ family, friends, community members, spouses, and even strangers under some conditions. Here we conduct a systematic review and meta-analysis of the experimental evidence that kindness interventions (for example, performing ‘random acts of kindness’) boost subjective well-being. Our initial search of the literature identified 489 articles; of which 24 (27 studies) met the inclusion criteria (total N = 4045). These 27 studies, some of which included multiple control conditions and dependent measures, yielded 52 effect sizes. Multi-level modeling revealed that the overall effect of kindness on the well-being of the actor is small-to- medium (δ = 0.28). The effect was not moderated by sex, age, type of participant, intervention, control con- dition or outcome measure. There was no indication of publication bias. We discuss the limitations of the current literature, and recommend that future research test more specific theories of kindness: taking kindness-specific individual differences into account; distinguishing between the effects of kindness to specific categories of people; and considering a wider range of proximal and distal outcomes. Such research will advance our un- derstanding of the causes and consequences of kindness, and help practitioners to maximise the effectiveness of kindness interventions to improve well-being.
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Journal of Experimental Social Psychology
journal homepage:
Happy to help? A systematic review and meta-analysis of the eects
of performing acts of kindness on the well-being of the actor
Oliver Scott Curry
, Lee A. Rowland
, Caspar J. Van Lissa
, Sally Zlotowitz
, John McAlaney
Harvey Whitehouse
Institute of Cognitive and Evolutionary Anthropology, University of Oxford, United Kingdom
Department of Psychology, Bournemouth University, United Kingdom
Methodology & Statistics, Social and Behavioural Sciences, Utrecht University, Netherlands
Department of Clinical Educational and Health Psychology, University College London, United Kingdom
School of Anthropology and Museum Ethnography, University of Oxford, United Kingdom
Erasmus School of Social and Behavioural Sciences, Erasmus University Rotterdam, Netherlands
Handling editor: Elizabeth Page-Gould
Positive psychology
Do acts of kindness improve the well-being of the actor? Recent advances in the behavioural sciences have
provided a number of explanations of human social, cooperative and altruistic behaviour. These theories predict
that people will be happy to helpfamily, friends, community members, spouses, and even strangers under some
conditions. Here we conduct a systematic review and meta-analysis of the experimental evidence that kindness
interventions (for example, performing random acts of kindness) boost subjective well-being. Our initial search
of the literature identied 489 articles; of which 24 (27 studies) met the inclusion criteria (total N= 4045).
These 27 studies, some of which included multiple control conditions and dependent measures, yielded 52 eect
sizes. Multi-level modeling revealed that the overall eect of kindness on the well-being of the actor is small-to-
medium (δ= 0.28). The eect was not moderated by sex, age, type of participant, intervention, control con-
dition or outcome measure. There was no indication of publication bias. We discuss the limitations of the current
literature, and recommend that future research test more specic theories of kindness: taking kindness-specic
individual dierences into account; distinguishing between the eects of kindness to specic categories of
people; and considering a wider range of proximal and distal outcomes. Such research will advance our un-
derstanding of the causes and consequences of kindness, and help practitioners to maximise the eectiveness of
kindness interventions to improve well-being.
1. Introduction
Do acts of kindness improve the well-being of the actor? Over the
past few decades, advances in the behavioural sciences have developed
numerous theories of human social, cooperative and altruistic beha-
viour. These theories kin altruism, mutualism, reciprocal altruism,
and competitive altruism make it possible to explain a variety of
dierent types of kindness (for example, love, sympathy, gratitude and
heroism). And they predict that people will be happy to helpfamily,
friends, community members, spouses, and even strangers under some
More recently, there has been growing interest in using kindness as
an intervention to boost subjective well-being. The idea that, for ex-
ample, random acts of kindnesscan boost the well-being not only of
the recipient, but also the actor, and could thereby provide a simple,
eective, inexpensive and widely-available means of addressing social
problems ranging from social isolation to more serious mental and
physical health conditions, has been taken up and promoted by a large
number of research groups, charities and government organisations
(Aked, Marks, Cordon, & Thompson, 2008;Aked & Thompson, 2011;
see S1; Huppert, 2009).
Here we outline existing theories of altruism and their relation to
kindness, and consider the predictions these theories make about well-
being. We then conduct a systematic review and meta-analysis of
Received 12 May 2017; Received in revised form 2 February 2018; Accepted 26 February 2018
The work on this article was supported by (R46536/CN001). We also thank the many researchers who generously responded to our requests for unpublished papers and
data. In particular we note the exceedingly helpful co-operation from Lara Aknin, Kate Hannibal, Ashley Whillans, Katherine Nelson, and Kristin Layous. And thanks to Rongqin Yu for
statistical advice, to Rosalind Arden for useful discussions, to Helena Cronin for comments on the manuscript, and to Alexandria Henke, Divia Joseph, Steve Rowland and Emma Seymour
for research assistance.
Corresponding author at: Institute of Cognitive and Evolutionary Anthropology, University of Oxford, 64 Banbury Road, Oxford, OX2 6PN, United Kingdom.
E-mail address: (O.S. Curry).
Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
0022-1031/ © 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (
Please cite this article as: Curry, O.S., Journal of Experimental Social Psychology (2018),
previous experimental studies of the eects of kind acts on the well-
being of the actor. And we end with a discussion of the limitations of
the existing literature, and make recommendations for future research.
2. The causes of kindness
Kindness refers to actions intended to benet others. Why and under
what circumstances are people kind to others? Why do people behave in
prosocial, cooperative and altruistic ways? Recent interdisciplinary
research has provided a wealth of answers to these questions (Curry,
Humans evolved from a long line of social primates, who have been
living in social groups for over 50 million years (Shultz, Opie, &
Atkinson, 2011). Group living aords numerous opportunities for var-
ious dierent types of mutually benecial cooperative interaction
(Lehmann & Keller, 2006;Nunn & Lewis, 2001;Sachs, Mueller, Wilcox,
& Bull, 2004). Natural selection has favoured a range of evolved psy-
chological mechanisms for taking advantages of these opportunities,
and realising the benets of cooperation. These mechanisms kin al-
truism, mutualism, reciprocal altruism, and competitive altruism
make it possible to identify and explain several dierent types of
2.1. Kin Altruism: people will be kind to their families
Natural selection favours kindness to genetic relatives, to family
members (Hamilton, 1964). Examples of such kin altruismare wide-
spread in nature (Gardner & West, 2014), most obviously in cases of
parental care (Royle, Smiseth, & Kölliker, 2012). Humans too possess
adaptations for detecting and delivering benets to kin (Lieberman,
Tooby, & Cosmides, 2007;Mateo, 2015), especially to ospring (Geary
& Flinn, 2001). Kin altruism can explain kindness in the form of love,
care, sympathy and compassion. And the theory predicts that these
tendencies will be elicited by others who exhibit cues of genetic relat-
edness, especially vulnerable children (Platek, Burch, Panyavin,
Wasserman, & Gallup Jr, 2002).
2.2. Mutualism: people will be kind to members of their communities
Natural selection favours the tendency to coordinate, collaborate
and be kind to others with whom the actor shares a common interest
team mates, group members, coalition partners. Such mutualisms’–for
the purpose of collective defence, or collaborative hunting are
widespread in nature (Bissonnette et al., 2015;Boinski & Garber, 2000;
Boos, Kolbe, Kappeler, & Ellwart, 2011;Harcourt & Waal, 1992), and
are an ancient and recurrent feature of human social life (Alvard, 2001;
Wrangham, 1999). This process has led, in humans, to a psychology
that forms and maintains groups (clubs, gangs, clans, sects, nations, and
so on), and acts to promote their interests (sometimes at the expense of
rival groups) (Balliet, Wu, & De Dreu, 2014). Mutualism can explain
kindness in the form of loyalty, solidarity, camaraderie, civic-mind-
edness, community spirit, and commitment to a cause greater than
oneself. The theory predicts that these tendencies will be elicited by
other members of the groups with which one identies (including
strangers) (Whitehouse & Lanman, 2014).
2.3. Reciprocal Altruism: people will be kind to those they might meet again
Natural selection favours kindness to those who might return the
favour at a later date (Axelrod, 1984;Trivers, 1971).
Surprisingly, few
if any examples of such reciprocal altruismhave been found in non-
human species (Amici et al., 2014;Clutton-Brock, 2009). But in
humans, reciprocal altruism is implemented by psychological me-
chanisms that: detect those in need of help, initiate cooperation, signal
recognition of favours received, keep track of who has returned the
favour and who has not, make amends for favours not returned, and
accept repentant cheats back into the fold (Cosmides & Tooby, 2005;
McCullough, Kurzban, & Tabak, 2013;Trivers, 1971). Thus, reciprocal
altruism can explain kindness in the form of sympathy (for those in
need), trust (initiating cooperation), returning favours, gratitude (for
favours yet to be returned), forgiveness and friendship. Reciprocal al-
truism predicts that these tendencies will most likely be elicited in re-
peated interactions where individuals expect to meet again, where one's
cooperative (or uncooperative) behaviour can be observed by others,
and towards others who have helped them in the past, or will be able to
help them in the future (Kraft-Todd, Yoeli, Bhanot, & Rand, 2015). This
can includes kindness to strangers: a kind act may be a way of making a
new friend; after all, a stranger is just a friend you haven't met yet
(Delton, Krasnow, Cosmides, & Tooby, 2011;Krasnow, Delton, Tooby,
& Cosmides, 2013).
2.4. Competitive Altruism: people will be kind to others when it enhances
their status
Natural selection also favours kindness that impresses peers and
attracts mates (Gintis, Smith, & Bowles, 2001;Maynard Smith & Price,
1973). Many animals resolve status competition by engaging in costly
displays of prowess (Hardy & Bria, 2013;Riechert, 1998). In humans,
and perhaps some other species (Zahavi & Zahavi, 1997), these displays
includes altruistic acts that benet the audience (Hardy & Van Vugt,
2006;Hawkes, 1991;Hawkes, O'Connell, & Blurton Jones, 2001;
Mazur, 2005;Miller, 2000;Smith & Bleige Bird, 2000). This competi-
tive altruismcan explain kindness in the form of generosity, bravery,
heroism, chivalry, magnanimity and public service. The theory predicts
that these tendencies will be elicited in the presence of rivals, or po-
tential mates, where acting altruistically may enhance one's status
(Raihani & Smith, 2015). This includes acts of kindness to strangers:
helping a stranger may improve your status whether the recipient is in a
position to return the favour or not (Barclay, 2011;Raihani & Bshary,
Thus, multiple theories kin altruism, mutualism, reciprocal al-
truism, competitive altruism explain multiple types of kindness. And
the human capacity for culturethe ability to invent and share new
ways of living (Boyd, Richerson, & Henrich, 2011;Pinker, 2010)has
allowed us to build and elaborate upon this benevolent biological
foundation, with rules, norms and other social institutions that further
inculcate and amplify cooperation and altruism (Hammerstein, 2003).
These theories predict that people will be motivated to be kind to fa-
mily, friends, colleagues, spouses, and even strangers under some
And the possession of such motivational systems leads us to
expect that helping others might make people happy.
3. The consequences of kindness
Subjective well-being including happiness, life-satisfaction and
positive aect refers to a range positively valenced psychological
states (Dolan & Metcalfe, 2012;OECD, 2013). Why would performing
kind acts improve well-being? Why would helping make you happy?
Broadly speaking, happiness can be seen as an internal reward system
for acting in ways that promote survival and reproduction (Buss, 2000).
Happiness is: a psychological reward, an internal signaling device that
tells us that an adaptive problem has been, or is in the process of being,
For further discussion of various subtypes of reciprocity, such as indirect and network
reciprocity, see (Roberts, 2008;Tanimoto, 2015)
Note that the argument here is that biology and culture have equipped us to help
automatically, intuitively, innocently there is no suggestion that people are necessarily
aware of the causes of their benevolent behaviour, or are acting from any ulterior motive.
The heart has its reasons of which reason knows nothing(Pascal, 1669).
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
solved successfully(Hill, DelPriore, & Major, 2013). From this per-
spective, it is no problem to explain why eatingor having sexmakes
people happy; these behaviours meet important adaptive goals. And, for
the reasons outlined above, it is equally straightforward to explain why
performing acts of kindness might make people happy: it is because
caring for family, maintaining coalitions, trading favours and increasing
status are also important adaptive goals (Schulkin, 2011). Indeed, we
might even expect helping others to produce more happiness than
helping yourself: it is precisely because helping others can sometimes
give a better return on investment than helping yourself that evolution
has favoured kindness in the rst place.
Thus, the evolutionary behavioural science approach to altruism
predicts that people will be happy to help family, friends, community
members, spouses, and even strangers under some conditions. This
prediction has received some support from the existing literature. A
large body of research has established an association between kindness
and well-being (Anik, Aknin, Norton, & Dunn, 2009;Konrath & Brown,
2013). However, much of this research has been correlational
showing, for example, that people who spend more money on others are
happier (Aknin, Barrington-Leigh, et al., 2013), or people who volun-
teer to help others are healthier (Jenkinson et al., 2013).
While such
correlational evidence is consistent with the prediction that people will
be happy to help others, it is not sucient to establish a causal re-
lationship between kindness and well-being. After all, it's possible that
helping makes you happy; but it could also be that happiness makes you
helpful, or it could be that some third variable health, income, or
personality makes you both happy and helpful. The distinction be-
tween correlation and cause is not a mere philosophical nicety; it is a
genuine dierence with important practical implications. In the ab-
sence of a clear causal connection, kindness interventions may not
work. They may waste time and money, or displace other more eective
interventions. Worse, they may be counter-productive. If happiness
causes helping (rather than the other way around), then forcing un-
happy people to help may make them less happy still.
In order to establish whether performing acts of kindness can cause
happiness, it is necessary to focus on the experimental literature. And so
we undertook a systematic review and meta-analysis of research that met
the following inclusion criteria: (a) experiments that randomly allocated
participants to (b) interventions involving kind behaviour and controls and
(c) subsequently measured and compared participant well-being.
4. Methods
In order to identify suitable experimental studies of the eects of
altruism on the altruist's well-being, we conducted searches of the sci-
entic databases Web of Science and PsychInfo for academic articles.
The most recent search was conducted on 16th November 2017. The
process is summarised in the ow diagram in Fig. 1. Searching topic,
abstracts and keywords, we used the search string: (kindness OR al-
truis* OR prosocial OR co-operat* OR cooperat*) AND (wellbeing OR
well-being OR happiness OR life satisfaction OR positive aect OR
negative aect OR PANAS) AND (experiment* OR control OR condition
OR random* OR empirical OR trial) NOT (mindfulness OR meditation
OR loving-kindness). This search identied 712 articles. To this we
added 36 articles identied by other means (following references in
books and journal articles, Google scholar searches, viewing academic
researchers' web-pages, reviewers' suggestions, and contacting authors
to request unpublished data). After removing duplicates, we were left
with 489 articles.
This initial set of 489 articles was screened. Two researchers (LAR
and OSC) read the titles and abstracts. Subsequently 432 articles were
excluded for not meeting the inclusion criteria. These articles were ei-
ther: (a) not experimental (for example, were qualitative or correla-
tional studies, or review papers); (b) did not involve kind behaviour (for
example, they involved hypothetical or recalled kindness); (c) did not
measure participant well-being (for example, they measured sub-
sequent kindness, or the happiness of the recipient); or were otherwise
otopic (for example, kindness in animal husbandry, climate change
and planetary wellbeing). Cases in which the researchers disagreed
were given greater scrutiny and discussed, and where no consensus was
reached, the articles were included in the next stage of the analysis.
The remaining 57 articles were then read in full, and assessed for
appropriateness for the meta-analysis (see S2 for the full list). This
process excluded a further 33 records (and several studies from in-
cluded articles) for reasons summarised in Table S1.
At the end of this
process we were left with 24 articles, containing a total of relevant 27
studies that had experimentally tested the hypothesis that kindness
causes well-being.
For each of these studies we coded the following characteristics:
mean age of sample
sex of participants
location of study
type of participant (for example, whether participants were typi-
cally developed individuals, as opposed to having been diagnosed
with some psychopathology)
type of intervention (for example, random act of kindness, proso-
cial purchase, charitable donation)
type of recipient (for example, whether family, friend, stranger)
type of control condition(s) (for example, no treatment, self-kind-
ness, other activity)
dependent measure(s) (for example, happiness, life-satisfaction)
size of the intervention group(s)
size of the control group(s)
eect size(s) (Cohen's d)
Eect sizes were either taken directly from the paper, or computed
from reported inferential or descriptive statistics (Lenhard & Lenhard,
2016). For the handful of studies that reported outcomes at multiple
time-points, we coded the eect closest in time to the intervention.
5. Results
5.1. Study characteristics
The characteristics of the 27 studies are presented in Table 1. These
27 studies included a total of 4045 participants (mean proportion
male = 35%, mean age = 25.04, SD = 11.05).
The majority of participants came from Canada, USA and Europe,
although there were also studies conducted in South Africa, Korea and
Vanuatu. Most participants were university students, although there
were also two studies with children, one study of Vanuatu villagers, and
one with elderly participants. Most were typically developed in-
dividuals, although two studies involved participants who scored
Even then the eects are modest. This meta-analysis of the relationship between
volunteering and health in the elderly found that volunteers were 22% less likely that
non-volunteers to die during the follow-up period of the studies (Jenkinson et al., 2013).
However, the import of this nding depends on the base-rate. By way of illustration, if on
average 10 out of 1000 (1%) non-volunteers die during the follow-up period, then a 22%
percent decrease means that 7.8 out of 1000 (0.78%) volunteers would die during the
same period. Moreover, as this review goes on to say: These ndings were not conrmed
by experimental studies.
The most highly cited paper in the kindness literature (with 597 citations at the time
of the last search) purports to provide evidence that kind acts boosts the well-being of the
actor (Lyubomirsky, Sheldon, & Schkade, 2005). However, the article does not report the
size of the sample, the dependent measure, or any inferential statistics (for example, eect
size or signicance). Email correspondence with the author revealed that the data are no
longer available.
These averages are approximate (~), because the age and sex ratio of the samples
were not available for some studies.
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
highly on measures of social anxiety.
The two most common interventions were acts of kindnessand
prosocial purchasing. Typical instructions for the acts of kindness
intervention were as follows:
During the coming week, please perform at least ve acts of
kindness per day and report on them in the evening, including the
responses of others that you received. Examples of acts of kindness
are: holding a door for someone at university, greeting strangers in
the hallway, helping other students in preparing for an exam, et-
cetera. It does not matter whether you address your acts of kindness
to people you know or not.
(Ouweneel, Le Blanc, & Schaufeli, 2014)
Prosocial purchasing interventions involved giving participants a
sum of money, and instructing them to spend it on someone else. Most
acts of kindnessinvolved a cost; but, the prosocial spendingstudies
that involved a windfall payment to the participant did not.
The recipients of kindness included colleagues and charities, but
were for the most part left unspecied, and could be anyone’–familiar
or unfamiliar, family, friend, community member of stranger.
Control conditions also varied. Some studies compared acting kindly
with doing nothing (thus possibly confounding the eects of kindness
with the eects of performing any novel fun activity), whereas others
compared acting kindly with some other non-social activity, or with
helping oneself.
Most studies used a self-report measure of subjective well-being,
happiness, life-satisfaction, or positive and negative aect. These in-
cluded the Subjective Happiness Scale (SHS; Lyubomirsky & Lepper,
1999), the Steen Happiness Index (SHI; Seligman, Steen, Park, &
Peterson, 2005), the Satisfaction With Life Scale (SWLS; Diener,
Emmons, Larsen, & Grin, 1985), the Positive Aect and Negative
Aect Scale (PANAS; Watson, Clark, & Tellegen, 1988) and Psycholo-
gical Flourishing (Lamers, Westerhof, Bohlmeijer, ten Klooster, &
Keyes, 2011). Three studies used more objective measures: two used
other-rated smiling, and one used other rated happiness.
Some studies had multiple control conditions, and/or multiple
outcome measures, and hence provided more than one eect size; there
were 52 in total.
5.2. Descriptive statistics
The eect size estimates ranged from 0.46 to 1.25 (M=0.25,
SD = 0.32). Sample sizes ranged from 26 to 474 participants
(M= 158.57, SD = 132.05). Several studies reported multiple eect
sizes (16, with most reporting one or two eect sizes).
5.3. Meta-analysis
Meta-analysis was conducted in R (R Core Team, 2017) and the R-
packages metafor (Viechtbauer, 2010), and metaforest (Van Lissa,
Full-text articles excluded
(n = 33)
1) No kind acts, just
recall n=3
2) Counting kind acts, no
new ones n=4
3) Expected or imaginary
kindness n=3
4) No control n=2
5) Comparing kindness
on other IV n=4
6) Kind acts embedded
with other positive
activities n=8
7) Incomplete description
of experiment n=1
8) Review or meta-
analysis n=3
9) Correlational n=3
10)Irrelevant DV n=2
Records after duplicates removed
(n = 489)
Studies included in
quantitative synthesis
(n = 27)
Full-text articles
assessed for eligibility
(n = 57)
Records excluded
(n = 432)
Records screened
(n = 489)
Additional records identified
through other sources
(n = 36)
Included Screening
Records identified through
database searching
(n = 712)
Fig. 1. Flow diagram of the search and selection procedure of studies.
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
Table 1
Main characteristics of studies included in the meta-analysis.
Study Sex Age Location Donor Intervention (IV) Control Recipient(s) Outcome (DV) n1 (I) n2 (C) d
Aknin, Barrington-Leigh, et al. (2013) Study 3 38 21.00 Canada/South
Typical Prosocial purchase Personal purchase Anonymous sick
PA 100 100 0.46
Aknin, Barrington-Leigh, et al. (2013) Study 3 38 21.00 Canada/South
Typical Prosocial purchase Personal purchase Anonymous sick
SWLS 100 100 0.13
Aknin, Broesch, Hamlin, & Van de
Vondervoort (2015)
Study 1 42 45.00 Vanuatu Typical Prosocial purchase Personal purchase Family/friends PA 13 13 0.93
Aknin et al. (2015) Study 2 70 ~3 Vanuatu Typical Donate own sweets Donate other
Puppet Smiling 20 20 0.30
Aknin, Dunn, Sandstrom, & Norton (2013) Study 3 34 21.00 Canada Typical Prosocial purchase Personal purchase Someone WB 25 25 0.24
Aknin, Fleerackers, & Hamlin (2014) 41 19.90 USA Typical Prosocial purchase Personal purchase Anonymous sick
PANAS 60 59 0.38
Aknin et al. (2014) 41 19.90 USA Typical Prosocial purchase Personal purchase Anonymous sick
ORH 60 59 0.44
Aknin, Hamlin, & Dunn (2012) 55 1.90 Canada Typical Donate own sweets Donate other
Puppet Smiling 20 20 0.46
Alden & Trew (2013) 28 19.56 Canada Socially anxious AK BE Anyone PA 43 40 0.59
Alden & Trew (2013) 28 19.56 Canada Socially anxious AK BE Anyone NA 43 40 0.16
Alden & Trew (2013) 28 19.56 Canada Socially anxious AK LD Anyone PA 43 43 0.54
Alden & Trew (2013) 28 19.56 Canada Socially anxious AK LD Anyone NA 43 43 0.42
Anik, Aknin, Norton, Dunn, & Quoidbach
Study 1 41 37.28 Australia Typical Prosocial purchase ($25) None Charity PANAS 41 48 0.15
Anik et al. (2013) Study 1 41 37.28 Australia Typical Prosocial purchase ($50) None Charity PANAS 44 48 0.49
Buchanan & Bardi (2010) 26 38.00 UK? Typical AK New acts Anyone SWLS 28 28 0.41
Buchanan & Bardi (2010) 26 38.00 UK? Typical AK No acts Anyone SWLS 28 28 0.62
Chancellor, Margolis, Jacobs Bao, &
Lyubomirsky (2017)
27 35.60 Spain Typical AK Receiver Co-worker SHS 16 34 *
Chancellor et al. (2017) 27 35.60 Spain Typical AK Receiver Co-worker SWLS 16 34 *
Chancellor et al. (2017) 27 35.60 Spain Typical AK None Co-worker SHS 16 33 *
Chancellor et al. (2017) 27 35.60 Spain Typical AK None Co-worker SWLS 16 33 *
Donnelly, Grant, Lamberton, Walker
Reczek, & Norton (2017)
Study 1 52 22.57 USA Typical Social recycling Trash/recycling Unknown lab
H 59 56 0.77
Donnelly et al. (2017) Study 1 52 22.57 USA Typical Social recycling Take item Unknown lab
H 59 59 0.85
Donnelly et al. (2017) Study 2b 50 37.77 USA Typical Social recycling Trash Unknown lab
PA 107 108 1.25
Dunn, Aknin, & Norton (2008) Study 3 26 College Canada Typical Prosocial purchase Personal purchase Anyone/charity H 23 23 0.67
Geenen, Hoheluchter, Langholf, & Walther
21 College Germany Typical Prosocial purchase Personal purchase Friends PANAS 34 34 0.70
Hanniball & Aknin (2016) 43 19.37 Canada Typical Helping behaviour: mapping out
course schedule
Helping self Colleague PANAS 51 56 0.46
Layous, Kurtz, Margolis, Chancellor,
Lyubomirsky (2017)
Study 1 16 18.55 USA Typical AK Track daily activity Someone known SHS 70 69 0.08
Layous et al. (2017) Study 1 16 18.55 USA Typical AK Track daily activity Someone known WB 70 69 0.20
Layous et al. (2017) Study 1 16 18.55 USA Typical AK Track daily activity Someone known EWB 70 69 0.26
Layous et al. (2017) Study 2 19 18.93 USA Typical AK Make self happier Other/one SHS 178 81 0.30
Layous et al. (2017) Study 2 19 18.93 USA Typical AK Make self happier Other/one WB 178 81 0.12
Layous, Lee, Choi, & Lyubomirsky (2013) 38 College
USA/Korea Typical AK Track locations Anyone WB 213 104 0.18
Layous, Nelson, Oberle, Schonert-Reichl,
& Lyubomirsky (2012)
na 10.60 Canada Typical AK Whereabouts Anyone SHSc 208 208 0.05
Layous et al. (2012) na 10.60 Canada Typical AK Whereabouts Anyone PAc 208 208 0.12
Layous et al. (2012) na 10.60 Canada Typical AK Whereabouts Anyone SWLSc 208 208 0.07
Martela & Ryan (2016) 36 20.40 USA Typical Benevolence Neutral activity Charity PA 34 42 0.55
Martela & Ryan (2016) 36 20.40 USA Typical Benevolence Neutral activity Charity NA 34 42 0.42
Mongrain, Chin, & Shapira (2011) 16 33.63 Canada Typical AK Memory Anyone SHI 237 237 0.08
(continued on next page)
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
2017), following the recommendations summarised in (Field & Gillett,
2010). We used three-level meta-analysis to account for dependent ef-
fect sizes within studies (Van den Noortgate, López-López, Marín-
Martínez, & Sánchez-Meca, 2015). Let y
denote the jobserved eect
sizes y, originating from kstudies. The multi-level model is then given
by the following equations:
=+ ∼
=+ ∼
=+ ∼
yβ Nσ
βθw w Nσ
θδb bNσ
ϵwhereϵ 0,
where (0, )
where (0, )
jk jk jk jk
jk kjk jk w
kkk b
The rst equation indicates that observed eect sizes are equal to
the underlying population eect size, plus sampling error ϵ
. The
second equation indicates that population eect sizes within studies are
a function of a study-specic true eect size, plus within-study residuals
. The third equation indicates that the distribution of study-specic
true eect sizes are distributed around an overall mean eect, with
between-study residuals b
. Results revealed that the overall eect size
estimate was δ= 0.28, 95% CI [0.16, 0.41], Z= 4.36, p< .001 (see
Fig. 2). This is a small-to-medium eect, approximately equivalent to an
increase of 0.6 on a standard 010 happiness scale (Helliwell, Layard, &
Sachs, 2016). The within-studies variance component σ
was negli-
gible, 0.00, 95% CI [ < 0.01, 0.02]. The between-studies variance σ
on the other hand, diered signicantly from zero, 0.08, 95% CI [0.04,
0.18]. The fact that the between-studies component was larger than the
within-studies component indicates that the variation in eect sizes was
primarily accounted for by dierences between studies, whereas dif-
ferences between eect sizes within the same studies were negligible.
Likelihood ratio tests also indicated that constraining the within-studies
variance to zero would not worsen model t, whereas constraining ei-
ther the between-studies variance or both variance components to zero
did lead to signicant deteriorations in model t (see Table 2). This
again indicates that there was substantial heterogeneity between
average eect sizes across studies, but not between eect sizes pub-
lished within the same studies.
File drawer analysis (Rosenthal, 1979) revealed that 1919 un-
published, led, or unretrieved studies averaging null results would be
required to bring the average unweighted eect size to nonsignicance.
Visual inspection of the Funnel plot (Fig. 3) did not clearly indicate
asymmetry, which could be a sign of publication bias. Begg's test of
funnel asymmetry (based on random-eects meta-analysis) similarly
did not indicate signicant bias, Z= 1.07, p= 0.28.
5.4. Moderation
We coded several potential theoretical and methodological moderators:
proportion of male participants, average age of the sample, type of parti-
cipant (typical, socially anxious), type of intervention (acts of kindness,
prosocial spending, other), type of control condition (nothing, neutral ac-
tivity, self-help, other), and outcome measure (happiness, life satisfaction,
positive or negative aect or emotion, other).
The small sample size limits our ability to include these moderators in
mixed-eects meta-analysis without risking overtting (modeling random
noise in the data, rather than true moderating eects). We therefore used
metaforest (Van Lissa, 2017) to screen for relevant moderators. This tech-
nique uses the machine learning algorithm random foreststo prevent
overtting, and to assess the importance of several potential moderators. An
added benet is that metaforest can capture non-linear relationships be-
tween moderators and eect size, and higher-order interactions. To this
end, many (in this case, 10,000) bootstrap samples are drawn from the
original data, and a models is estimated on each bootstrap sample. Then,
each model's performance is evaluatedoncasesnotpartofitsbootstrap
sample, yielding an estimate of explained variance in new data, R
conducted random-eects weighted metaforest, with clustered boot-
strapping to account for the multilevel structure of the data (n
= 10000,
Table 1 (continued)
Study Sex Age Location Donor Intervention (IV) Control Recipient(s) Outcome (DV) n1 (I) n2 (C) d
Mongrain et al. (2011) 16 33.63 Canada Typical AK Memory Anyone CES-D 237 237 0.15
Nelson et al. (2015) 53 19.98 USA/Korea Typical AK Work activity Anyone SHS 54.5 54.5 0.23
Nelson et al. (2015) 53 19.98 USA/Korea Typical AK Work activity Anyone SWLS 54.5 54.5 0.27
Nelson et al. (2015) 53 19.98 USA/Korea Typical AK Work activity Anyone PE 55 55 0.09
Nelson et al. (2015) 53 19.98 USA/Korea Typical AK Work activity Anyone NE 55 55 0.06
Nelson, Layous, Cole, & Lyubomirsky
40 29.95 USA Typical AK Track activities Other/world PE 238 116 0.30
Nelson et al. (2016) 40 29.95 USA Typical AK Track activities Other/world NE 238 116 0.36
Nelson et al. (2016) 40 29.95 USA Typical AK Track activities Other/world PF 238 116 0.15
Nelson et al. (2016) 40 29.95 USA Typical AK Self Other/world PE 238 116 0.20
Nelson et al. (2016) 40 29.95 USA Typical AK Self Other/world NE 238 116 0.16
Nelson et al. (2016) 40 29.95 USA Typical AK Self Other/world PF 238 116 0.19
O'Connell, O'Shea, & Gallagher (2016) 43 34.17 USA Typical AK List activities Social network SHS 28 12 0.02
O'Connell et al. (2016) 43 34.17 USA Typical AK Self Social network SHS 28 31 0.12
Ouweneel et al. (2014) Study 2 16 20.88 Netherlands Typical AK Neutral activity Anyone PE 25 24 0.27
Ouweneel et al. (2014) Study 2 16 20.88 Netherlands Typical AK Neutral activity Anyone NE 25 24 0.27
Trew & Alden (2015) 26 20.47 Canada Socially anxious AK Social exposure Anyone PA 38 41 0.05
Trew & Alden (2015) 26 20.47 Canada Socially anxious AK List activities Anyone PA 36 41 0.33
Whillans, Dunn, Sandstrom, Dickerson, &
Madden (2016)
Study 2 50 72.02 USA Hypertense Prosocial purchase Personal purchase Anyone WB 36 37 0.19
Note. AK = acts of kindness; CES-D = Center for Epidemiological Studies Depression Scale; EWB = Eudaimonic Well-Being; H = happiness; NA = negative aect; NE = negative emotions; ORH = Other-Report Happiness; PA = positive aect;
PANAS = Positive and Negative Aect Scale; PF = Psychological Flourishing; SHI= Steen Happiness Index; Sex = % men in sample; SHS = Subjective Happiness Scale; SWLS = Satisfaction With Life Scale; WB = well-being. * = Statistics needed
to calculate eect size were not reported in the paper, nor available from the authors.
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
Fig. 2. Forest plot for the eect of kindness acts on actor's well-being.
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
= 2). We replicated the analysis 100 times to ensure the reliability of
ndings. The median estimated explained variance in out-of-bootstrap cases
was negative (R
=0.11), with a large standard deviation across re-
plications (SD = 0.19). When R
is negative, this means that the average
eect size is a better predictor of out-of-bootstrap cases than the model-
implied predictions. In other words, the model did not capture general-
izable relationships between the moderators and eect size, and we did not
nd evidence for associations between the moderators and eect size.
6. Discussion
The results of this systematic review and meta-analysis of the experi-
mental kindness literature suggests that performing acts of kindness im-
proves the well-being of the actor (δ=0.28). The eect of kindness is
small-to-medium comparable to other positive psychology interventions
(such as mindfulness,positive thinkingand counting your blessings;
d=0.34, Bolier et al., 2013; d = 0.31, Sin & Lyubomirsky, 2009;
d=0.44, Weiss, Westerhof, & Bohlmeijer, 2016).
The eect was not
moderated by sex, age, type of participant, intervention, control condition
or outcome measure. And there was no evidence of publication bias. To-
gether, these results suggest that policy-makers and practitioners are cor-
rect to see kindness interventions as eective ways of improving well-
being. And they support the general claim that, as social animals, humans
possess a range of psychological mechanisms that motivate them to help
others, and that they derive satisfaction from doing so.
However, in interpreting these results, a number of limitations
should be kept in mind.
First, most of the reviewed studies were under-powered. The average
sample size per condition was N= 79; this gives power of only β=0.42 to
detect a typical eect size of d = 0.28. In order to detect such an eect with
power β= 0.80, future researchers should use a sample size of at least 202
per group (Faul, Erdfelder, Lang, & Buchner, 2007).
Second, most of the reviewed studies used non-clinical samples of
students, from Western, Educated, Industrial, Rich, Democratic
societies (W.E.I.R.D.; Henrich, Heine, & Norenzayan, 2010). Thus it
remains unclear whether the current ndings would generalise to
clinical samples of participants diagnosed with specic mental health
problems, in non-WEIRD societies. Future research should employ more
representative community samples (perhaps focussing on social dis-
orders; Qualter et al., 2015), in a wider variety of cultures.
Third, earlier we dened kindness as actions intended to benet
others. The studies reviewed here varied whether actions benetting
others were performed, they did not vary whether the benets were
intended or not in other words, they did not manipulate the motive
behind the action. Previous research has found an association between
motive and outcome; one longitudinal study found that volunteers
motivated by a desire to help others lived longer than non-volunteers,
but that volunteers motivated by a desire to help themselves did not
(Konrath, Fuhrel-Forbis, Lou, & Brown, 2012). If this relationship is
causal, then policy-makers should be aware that encouraging people to
help others because of the benets to themselves may be counter-pro-
ductive it may, somewhat paradoxically, mitigate or eliminate the
eect. Further experimental research will be needed to investigate the
role of intention on the benets of helping others.
Fourth, although the nding is consistent with the general evolu-
tionary account of altruism outlined above, existing research has not
tested the more ne-grained predictions that arise from the more spe-
cic theories of helping (kin altruism, mutualism, reciprocal altruism
and competitive altruism). For example, there has been little systematic
investigation of whether dierent people benet more from performing
acts of kindness under dierent conditions. And studies have not sys-
tematically varied the type of recipient, for example family, colleague,
friend, stranger. In fact, in most cases the recipient was left unspecied
that is, they could be anyone. And so we do not know whether:
people who have lost touch with their families derive more pleasure
from acts of kin altruism; or whether people are happier giving to
children as opposed to adults. We do not know whether, as mutualism
predicts, people are be happier giving to in-group as opposed to out-
groups; or whether, as reciprocal altruism predicts, people are happier
giving to unlucky, as opposed to lazy, recipients (Petersen, 2012). Nor
do we know whether ambitious people (with more resources to spare)
seeking status are happier engaging in acts of competitive altruism,
whether single people who are courting are happier helping help po-
tential mates, or whether there are any sex dierences in the satisfac-
tion derived from dierent kinds of helping (Balliet, Li, Macfarlan, &
Van Vugt, 2011). Thus future work should seek to ll these gaps in our
understanding. There is already a large literature on whether people
behave more or less altruistically to specic types of people; it would be
fairly straightforward to add measures of subjective well-being to re-
plications and extensions of these designs.
Fifth and nally, existing research has tended to look at the im-
mediate eects of kindness well-being. Hence it is not clear what the
longer-term eects of the intervention, on well-being or more distal
measures, may be. After all, previous research suggests that such eects
are likely to be short-lived –‘happinessprovides an immediate reward
for behaviour that has long-term benets, and research on the hedonic
treadmillsuggests that people might have a set pointthat they return
to whatever happens to them, good or bad (Ryan & Deci, 2001). If the
function of altruistic behaviour is to help families, make new friends,
improve communities, increase status, or nd a mate, then it would be
instructive for future experiments to measure these hypothesised long-
term benets. Do people allocated to the kindness condition report
better relations with their families? More identication with their
communities? More friends? More recognition and honours? More
pride in one's achievements (Sznycer et al., 2017)? More sexual part-
ners (Arnocky, Piché, Albert, Ouellette, & Barclay, 2016)? More com-
mitted relationships (Kogan et al., 2010)? More resilient marriages? If
so, then future research might be able to nally connect the two types
of happiness short-term hedonic pleasure, and long-term eudaemonic
components of the good life that have hitherto remained apart.
Table 2
Model t indices.
Three-level model 3 22.14 28.16 8.07
Within-studies variance constrained 2 20.14 24.15 8.07 0 1
Between-studies variance constrained 2 33 36.76 14.37 12.61 0
Both variance components constrained 1 78 80.25 38.12 60.1 0
Note. Signicance of variance components is assessed by constraining them to zero, and
examining the signicance of a log-likelihood (ll) ratio test (LRT) comparing the con-
strained model to the full three-level model.
Fig. 3. Funnel plot for the eect of acts of kindness on actor's well-being.
Although see Coyne (2014a, 2014b) for critical commentary on (Sin & Lyubomirsky,
2009) and (Bolier et al., 2013).
O.S. Curry et al. Journal of Experimental Social Psychology xxx (xxxx) xxx–xxx
7. Conclusion
Helping others makes you happy, but the eect is relatively modest.
Further empirical work testing the implications of more specic the-
ories of social, cooperative and altruistic behaviour is needed to de-
termine whether the eect might be larger for some types of helpers,
when helping some types of recipients. This research will advance our
understanding of the causes and consequences of kindness, and help
practitioners to maximise the eectiveness of kindness interventions.
Open practices
The data and analysis script for this study are available on its Open
Science Framework page (
Appendix A. Supplementary data
Supplementary data to this article can be found online at https://
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... The present non-deceptive placebo study aimed to promote engagement in another type of positive behavior that is associated with well-being: acts of kindness (AoKs; [11][12][13][14][15][16]). Kindness includes caring, affection, generosity, consideration, and concern toward others. ...
... In summary, engaging in AoKs has been shown to be a useful method for increasing subjective well-being (also see meta-analysis by Curry et al. [12]). At the same time, various factors can hinder the performance of AoKs and thus prevent their positive effects (e.g., time pressure). ...
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Placebos have often been used to reduce emotional distress but rarely to increase positive feelings. The present study investigated whether a placebo can promote acts of kindness (AoKs) that are associated with emotional well-being. A total of 160 university students were asked to perform an AoK daily for one week. They evaluated their emotional state (feelings of pleasantness, arousal, satisfaction) directly before and after the AoKs. This was monitored via a smartphone app. One group performed each AoK after taking a non-deceptive placebo; the other group received no placebo. Before and after the one-week program, the participants completed three questionnaires that assessed satisfaction with life, positive/negative affect, and flourishing. The participants reported higher pleasantness directly after engaging in an AoK and more satisfaction with life after the program. The motivation to carry out AoKs decreased strongly over the week. However, placebo receivers completed more AoKs than the no-placebo group. The results indicate that placebo treatment can promote the performance of acts of kindness.
... Although inconsistent findings have been reported, the bulk of the evidence indicates that being compassionate towards others results in greater social connectedness, improved physical health, and better psychological wellbeing (Crocker et al., 2017;Curry et al., 2018;Neff & Seppälä., 2016). Recently, a handful of ESM studies have provided further support for the benefits of other-compassion (and its related constructs such as empathy) on well-being (Depow et al., 2021;Runyan et al., 2019;Steger et al., 2008). ...
... Theoretically, there is a strong rationale for self-other harmony (Crocker & Canevello, 2008;Wiklund Gustin & Wagner, 2013;Hermanto & Zuroff, 2016). Buddhist philosophy emphasises the interconnection between self and others, and research generally supports this (Crocker et al., 2017;Curry et al., 2018;Depow et al., 2021;Runyan et al., 2019). Yet correlational research tends to find a moderate association between self-and othercompassion (r<0.50; ...
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Objectives This study examined the role of self-other harmony in the relations between self-compassion, other-compassion, and well-being. Past research has shown self- and other-compassion to be positively related. But we hypothesised that self-compassion can be perceived as incompatible with other-compassion, and that self-compassion and other-compassion might be uncorrelated or negatively correlated in daily life for some individuals. We termed this pattern lack of self-other harmony in compassion and hypothesised that it would undermine the benefits of compassion. Method Using an experience sampling method in patients (n=154) with a variety of diagnoses, we measured self-compassion, other-compassion, life-satisfaction, mood, and contextual variables six times per day for 42 time points. Results For most participants, self-compassion was positively associated with other-compassion. However, there was substantial heterogeneity in this effect. The degree of self-other harmony moderated the link between compassion directed towards self or other and well-being. Higher levels of compassion were associated with higher levels of well-being, but only for those who experienced the harmony. When the two forms of compassion were not in harmony, levels of self/other-compassion were largely unrelated to well-being. Conclusions The findings emphasise the importance of personalised compassion interventions rather than a one-size-fits-all approach. Increasing self-compassion or other-compassion is likely to improve well-being for most people. However, for a minority lacking the self-other harmony, it may be necessary to assess their interpretation of self- and other-compassion, then work with them to promote the compassion balance optimal for their well-being. Preregistration This study is not preregistered.
... The increase in positive emotions, reduction in negative emotions, and improvement in life satisfaction are likely important results of social support provision. In addition, social exchange theory believes that human behavior is dominated by exchange activities that can bring rewards and follow the principle of reciprocity and equality; providing emotional support to others can improve their emotions and create positive emotions and life satisfaction [23]. ...
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Background Social support consists of receipt and provision in the interpersonal exchange process. Many studies have explored and verified the effect of received social support. This study focuses on whether and when social support provision can benefit the providers’ positive psychological capital and subjective well-being. Methods A sample of 732 Chinese undergraduates with low socioeconomic status completed questionnaires on social support provision, psychological capital, life satisfaction, positive affect, negative affect, and sense of indebtedness. Results The correlation and regression analyses showed that impoverished college students’ social support provision was positively associated with life satisfaction, positive affect, and psychological capital and negatively associated with negative affect. The interaction between the sense of indebtedness and social support provision was negatively associated with life satisfaction, positive affect, and psychological capital, not significantly associated with negative affect. Conclusion The results demonstrated that giving social support can be as beneficial as receiving social support, and the sense of indebtedness can limit the benefits. Individuals with a lower sense of indebtedness are more likely to benefit from social support provision. The findings have implications for marginalized groups’ subjective well-being and positive psychological capital and show the necessity of guiding individuals to provide social support while maintaining their autonomy.
... The meso level is interpersonal and explores behaviors or actions that aim to benefit a person or a small group. This level includes behaviors such as helping [31], acts of kindness [32], altruism [33], caring [34], social support [35], prosocial spending [36], generosity [37], Organizational Citizenship Behaviors [38] and heroism [39]. ...
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Work on callings has burgeoned in the past 20 years, yet recent reviews exposed a lack of conceptual clarity and disagreements around its definition, components and measures. One lingering point of contention revolves around the element of prosociality: is a calling orientation primarily motivated by self-interest, prosocially orientated, or a mix of both? This conceptual paper reviews and examines the pro-self and prosocial component of a calling outlook, by examining and comparing the ways in which they feature in different calling subtypes: classic, neoclassic and modern callings. Our analysis suggests that these subtypes vary in where they are located on a pro-self-proso-cial continuum: classic callings are located on the prosocial side of the axis, modern callings are located on pro-self side of the axis, and neoclassic callings can be situated in the middle of the continuum , integrating self-orientated and other-orientated motivations. Our analysis further suggests that these calling subtypes draw on divergent value systems: classic callings are propelled by self-transcendent values, modern callings are driven by self-actualization motivations, and neoclassic callings integrate both value systems. We therefore argue that the subjective experiences of pursuing a calling within each subtype pathway differ, although they may culminate in similar outcomes. The paper offers a novel framework for analyzing people's calling that draws on their values.
... As part of the overarching principle, the altruistic values provoke a feeling of warm glow as a psychological reward (Hartmann et al., 2017;Hartmann & Apaolaza-Ibáñez, 2012), despite the cost of time, money, or efforts (Walker & Chapman, 2003). Moreover, the feeling of warm glow makes people feel good and helps improve their well-being (Curry et al., 2018). Thus, tourists may enhance their well-being by doing the right thing (i.e. ...
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Recent discursive approaches to im/politeness have emphasised the significance of exploring non-academic understandings of im/politeness. Pursuing this line of research, the data for this paper come from a questionnaire distributed to 100 undergraduate female university students. The informants were asked to provide some attributes of a polite person and offer examples of a person or behaviour that impressed them as being polite. The aim was to elicit the respondents’ perceptions of what constitutes politeness. The results show that the prevalent attributes of a polite person for these informants are helpfulness and unconditional respect, along with kindness. These constitute a web of closely related concepts based on goodness and genuine concern for the other, with respectfulness and kindness probably motivating helpfulness. This finding suggests that non-academic understandings of politeness are broader and not confined to language use, which has been the locus of most im/politeness research.
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Statistical significance specifies, if a result may not be the cause of random variations within the data. But not every significant result refers to an effect with a high impact, resp. it may even describe a phenomenon that is not really perceivable in everyday life. Statistical significance mainly depends on the sample size, the quality of the data and the power of the statistical procedures. If large data sets are at hand, as it is often the case f. e. in epidemiological studies or in large scale assessments, very small effects may reach statistical significance. In order to describe, if effects have a relevant magnitude, effect sizes are used to describe the strength of a phenomenon. The most popular effect size measure surely is Cohen's d (Cohen, 1988), but there are many more. On https:// , you will find online calculators for Cohen's d, Glass' Delta, Hedges' g, Odds Ratio, Eta Square, calculation of effects from dependent and independent t-tests, ANOVAs and other repeated measure designs, non-parametric effect sizes (Kruskal Wallice, Number Needed to Treat, Common Language Effect Size), conversion tools and tables for interpretation. The code for computing these measures is avaliable as Javascript in the header of the source code of webpage.
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A functional analysis of prosociality considers how predispositions for prosocial behavior prompt, reinforce, and propagate kind behaviors in the real world. To examine the effects of practicing, receiving, and observing everyday prosociality—as well as the mechanisms underlying these effects—we randomly assigned employees in a Spanish corporate workplace (N = 111) to be Givers, Receivers, and Controls. Givers practiced 5 acts of kindness for a personalized list of Receivers over 4 weeks. We found that Givers and Receivers mutually benefited in well-being in both the short-term (e.g., on weekly measures of competence and autonomy) and the long-term (e.g., Receivers became happier after 2 months, and Givers became less depressed and more satisfied with their lives and jobs). In addition, Givers’ prosocial acts inspired others to act: Receivers paid their acts of kindness forward with 278% more prosocial behaviors than Controls. Our results reveal that practicing everyday prosociality is both emotionally reinforcing and contagious (inspiring kindness and generating hedonic rewards in others) and that receiving everyday prosociality is an unequivocally positive experience (which may further reinforce Givers’ actions). Prosociality’s benefits shed light on its surprising ubiquity in humanity compared with our closest evolutionary cousins.
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Significance Cross-cultural tests from 16 nations were performed to evaluate the hypothesis that the emotion of pride evolved to guide behavior to elicit valuation and respect from others. Ancestrally, enhanced evaluations would have led to increased assistance and deference from others. To incline choice, the pride system must compute for a potential action an anticipated pride intensity that tracks the magnitude of the approval or respect that the action would generate in the local audience. All tests demonstrated that pride intensities measured in each location closely track the magnitudes of others’ positive evaluations. Moreover, different cultures echo each other both in what causes pride and in what elicits positive evaluations, suggesting that the underlying valuation systems are universal.
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Consumers are often surrounded by resources that once offered meaning or happiness but that have lost this subjective value over time—even as they retain their objective utility. We explore the potential for social recycling—disposing of used goods by allowing other consumers to acquire them at no cost—to transform unused physical resources into increased consumer happiness. Six studies suggest that social recycling increases positive affect relative to trash, recycling, and donations of goods to nonprofit organizations. Both perceptions of helping the environment and helping other people drive this increase in positive affect. We conclude that social recycling offers a scalable means for reengineering the end of the consumption cycle to transform unused resources into happiness. We suggest that further research should continue to enrich a general theory of disposition, such that we are able to maximize the ecological, interpersonal, and community utility of partially depleted resources.
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Background There is a rapidly growing interest in psychological well-being (PWB) as outcome of interventions. Ryff developed theory-based indicators of PWB that are consistent with a eudaimonic perspective of happiness. Numerous interventions have been developed with the aim to increase PWB. However, the effects on PWB measured as coherent outcome have not been examined across studies yet. This meta-analysis of randomized controlled trials of behavioral interventions aims to answer the question whether it is possible to enhance PWB. Methods A systematic literature search was performed in PsycINFO, Cochrane and Web of Science. To be included, studies had to be randomized controlled trials of behavioral interventions with psychological well-being as primary or secondary outcome measure, measured with either Ryff’s Psychological Well-Being Scales or the Mental Health Continuum—Short Form. The meta-analysis was performed using a random effects model. From the 2,298 articles found, 27 met the inclusion criteria. The included studies involved 3,579 participants. Results We found a moderate effect (Cohen’s d = 0.44; z = 5.62; p < .001). Heterogeneity between the studies was large (Q (26) = 134.12; p < .001; I2 = 80.62). At follow-up after two to ten months, a small but still significant effect size of 0.22 was found. There was no clear indication of publication bias. Interventions were more effective in clinical groups and when they were delivered individually. Effects were larger in studies of lower quality. Conclusions It appears to be possible to improve PWB with behavioral interventions. The results are promising for the further development and implementation of interventions to promote PWB. Delivering interventions face-to-face seems to be the most promising option. We recommend to keep including clinical groups in the research of psychological well-being. Heterogeneity is a limitation of the study and there is need for more high-quality studies.
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A number of studies have shown that prosocial behavior is associated with enhanced well-being, but most prior experimental studies have involved actual or potential face-to-face contact with the beneficiary. To establish that it is prosocial behavior itself, and not only an increased sense of social relatedness to the recipient that improves well-being, participants (n = 76) were invited to play a simple computer game, where half were made aware of a chance to have an anonymous prosocial impact through gameplay. As compared to the control condition, this group experienced more positive affect, meaningfulness and marginally more vitality. Going beyond self-reported outcomes, they also demonstrated better post-game performance on a subsequent Stroop task, providing behavioral evidence for the positive effects of prosocial behavior. Also supported was the hypothesis that these positive effects of prosocial behavior on well-being were mediated by subjectively assessed autonomy and competence need satisfactions.
In order for non-kin altruism to evolve, altruists must receive fitness benefits for their actions that outweigh the costs. Several researchers have suggested that altruism is a costly signal of desirable qualities, such that it could have evolved by sexual selection. In two studies, we show that altruism is broadly linked with mating success. In Study 1, participants who scored higher on a self-report altruism measure reported they were more desirable to the opposite sex, as well as reported having more sex partners, more casual sex partners, and having sex more often within relationships. Sex moderated some of these relationships, such that altruism mattered more for men's number of lifetime and casual sex partners. In Study 2, participants who were willing to donate potential monetary winnings (in a modified dictator dilemma) reported having more lifetime sex partners, more casual sex partners, and more sex partners over the past year. Men who were willing to donate also reported having more lifetime dating partners. Furthermore, these patterns persisted, even when controlling for narcissism, Big Five personality traits, and socially desirable responding. These results suggest that altruists have higher mating success than non-altruists and support the hypothesis that altruism is a sexually selected costly signal of difficult-to-observe qualities.