Exploring mental toughness in soccer players of different levels of performance

Abstract

The objective of the present study was to assess mental toughness in two groups of soccer players of different levels of performance. The participants included 242 male soccer players, ranging from 14 to 19 years of age who participated in official competitions for under 16s and under 19s. The Mental Toughness Index (MTI) was used and they were asked three questions related to their perception of their capacity to reach higher levels. Results show significant differences between under 16 players and under 19 players. Some differences were also observed between players of UD Las Palmas and the other teams. Overall, results appear to indicate that from an early age, some differences in regard to mental toughness can be found depending on the level of performance. This study provides data of very young athletes and uses an instrument which had never been used on Spanish soccer players. Further research in this field would be interesting, focusing on younger subjects and other individual and team sports.

Full text

REVISTA IBEROAMERICANA DE PSICOLOGÍA DEL EJERCICIO Y EL DEPORTE Vol. 13 nº 2 pp. 297-303
ISSN 1886-8576
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº 2 (2018)
297
Manuscrito recibido: 25/07/2017
Manuscrito aceptado: 23/01/2018
Dirección de contacto: Félix Guillén.
Facultad de Ciencias de la
Educación. C/. Santa Juana de Arco,
1. 35004 Las Palmas de Gran
Canaria, Spain.
Correo-e: felix.guillen@ulpgc.es
EXPLORING MENTAL TOUGHNESS IN SOCCER PLAYERS OF DIFFERENT LEVELS OF
PERFORMANCE
Félix Guillén & Jorge Santana
Universidad de Las Palmas de Gran Canaria
ASBTRACT: The objective of the present study was to assess mental toughness in two groups of
soccer players of different levels of performance. The participants included 242 male soccer
players, ranging from 14 to 19 years of age who participated in official competitions for under
16s and under 19s. The Mental Toughness Index (MTI) was used and they were asked three
questions related to their perception of their capacity to reach higher levels. Results show
significant differences between under 16 players and under 19 players. Some differences were
also observed between players of UD Las Palmas and the other teams. Overall, results appear
to indicate that from an early age, some differences in regard to mental toughness can be found
depending on the level of performance. This study provides data of very young athletes and
uses an instrument which had never been used on Spanish soccer players. Further research in
this field would be interesting, focusing on younger subjects and other individual and team
sports.
KEYWORDS: Mental Toughness, Mental Toughness Index, soccer, Young people, Spanish.
EXPLORANDO LA FORTALEZA MENTAL EN JÓVENES FUTBOLISTAS DE DIFERENTES NIVELES
DE RENDIMIENTO
RESUMEN: El objetivo del presente estudio era evaluar la fortaleza mental de dos grupos de
futbolistas con diferentes niveles de rendimiento. Los participantes fueron 242 futbolistas
masculinos, con edades comprendidas entre los 14 y 19 años y participantes en competición
oficial en categorías cadete y juvenil. Se administró el Mental Toughness Index (MTI) y se les
planteó tres preguntas relacionadas con su percepción en cuanto a su capacidad de alcanzar
niveles más altos. Los resultados muestran diferencias significativas entre jugadores cadetes y
juveniles. También se aprecian algunas diferencias entre jugadores de la UD Las Palmas y de los
otros equipos. En general, los resultados parecen indicar que ya desde edades tempranas se
aprecian ciertas diferencias en la fortaleza mental según el nivel de rendimiento. Este estudio
procura datos de deportistas muy jóvenes y la utilización de un instrumento no utilizado en
futbolistas españoles. Sería interesante que futuras investigaciones incluyeran sujetos de
edades aún más tempranas y que también sean considerados otros deportes tanto colectivos
como individuales.
PALABRAS CLAVE: Fortaleza mental, Mental Toughness Index, fútbol, jóvenes, español.
EXPLORANDO A ROBUSTEZ MENTAL EM JOVENS FUTEBOLISTAS DE DIFERENTES NÍVEIS DE
RENDIMENTO
RESUMO: O objetivo do presente estudo foi avaliar a robustez mental em dois grupos de
futebolistas com diferentes níveis de rendimento. Os participantes foram 242 futebolistas
masculinos, com idades compreendidas entre os 14 e os 19 anos, que competiam oficialmente
nas categorias cadete e juvenil. Foi administrado o questionário Mental Tougness Index (MRI) e,
adicionalmente, foram colocadas três questões relacionadas com a sua perceção relativamente
à capacidade para atingirem níveis mais elevados. Os resultados revelaram diferenças
significativas entre jugadores cadetes e juvenis. Também se constatou a existência de algumas
diferenças significativas entre jogadores de la UD Las Palmas e das restantes equipas. Em geral,
os resultados parecem indicar que já desde idades iniciais se observam certas diferenças na
robustez mental dependendo do nível de rendimento. Este estudo centrou-se na análise de
dados de desportistas muito jovens e na utilização de um instrumento não utilizado em
futebolistas espanhóis. Seria interessante que futuras investigações se debruçassem sobre
futebolistas ainda mais jovens bem como sobre outros desportos, sejam eles coletivos ou
individuais.

Félix Guillén & Jorge Santana
298
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº2 (2018)
PALAVRAS-CHAVE robustez mental, Mental Toughness Index, futebol, jovens, espanhol.
Over the past 15 years, a lot of emphasis has been placed on the
concept of mental toughness in the field of Sport and Exercise
psychology. Mental toughness has been defined as ‘‘a collection
of values, attitudes, emotions, and cognitions that influence the
way in which an individual approaches, responds to, and
appraises demanding events to consistently achieve his or her
goals’’ (Gucciardi, Gordon, & Dimmock, 2009, p. 54). However,
Middleton, Marsh, Martin, Richards, and Perry (2004) defined
mental toughness as “an unshakeable perseverance and
conviction towards some goal despite pressure or adversity”. The
many definitions and understandings of mental toughness have
caused controversy and a considerable number of reviews on
this literature have been written (Connaughton et al., 2008;
Cowden, 2017; Crust, 2008; Gucciardi, 2017a; Jones, Hanton &
Connaughton, 2002) this has led to independent streams of
empirical research (for reviews, see Gucciardi & Gordon, 2011),
yet more agreement on common elements of a concept is
required before such bodies of knowledge can contribute to its
evolution (Suddaby, 2010).
The personal nature of mental toughness is the most striking
aspect of the definitions given so far as it is a quality which lies
within the individual. The notion of being able to resist or endure
challenging or adverse situations is also inherent within these
definitions. For instance, Jones et al. (2002) associated mental
toughness to “being more consistent and superior to
opponents”, whereas Coulter, Mallett & Gucciardi (2010)
described it as the presence of some or the entire collection of
experientially developed and inherent values, attitudes,
emotions, cognitions, and behaviors that influence the way in
which an individual approaches, responds to, and appraises both
negatively and positively construed pressures, challenges, and
adversities to consistently achieve his or her goals.
Likewise, mental toughness is considered to be a
multidimensional construct that encompasses a variety of
cognitive, emotional, and behavioral dimensions and it is
important in sports as it is related to performance (Bull,
Shambrook, James & Brooks, 2005; Clough, Earle, & Sewell, 2002;
Connaughton, Wadey, Hanton & Jones, 2008; Crust & Clough,
2005; Jones et al., 2007).
Despite the literature acquired, Jones et al. (2002) lament the
lack of conceptual clarity which is still present surrounding
mental toughness as, although significant progress has been
made and some of the key characteristics of this construct have
been agreed upon (Crust, 2007), there are still important
loopholes.
In any case, this concept should not be mistaken for others
which are closely related such as hardiness, coined by Kobasa
(1979) given that they are not exactly the same (Clough et al.,
2002; Crust, 2007; Gucciardi, 2017a; Madrigal, Hamill & Gill, 2013)
or resilience (Coulter et al., 2010; Cowden, 2017; Gucciardi,
Hanton, Gordon, Mallett, & Temby, 2015).
The methodology used for the research, whether it is
qualitative or quantitative, has consistently shown a series of
components, characteristics or attributes that appear such as
self-confidence, commitment, self-motivation, advancing in
competence and challenges, conserving psychological control
under pressure, optimism resilience, hope, perseverance,
focusing and concentration abilities (Crust, 2007; Crust & Swann,
2011; Gould et al., 2002; Gucciardi et al., 2008; Sheard, 2010;
Stajkovic, 2006). As shown, this construct includes a wide range
of components, characteristics or attributes (Gould, Dieffenbach
& Moffett, 2002; Guillén & Laborde, 2014).
Early literature on mental toughness, that goes as far back as
the end of last century and the beginning of this century, was
initially of qualitative nature (Bull, et al., 2005; Jones, Hanton &
Connaughton, 2002; Middleton et al., 2004; Thelwell Weston &
Greenlees, 2005), and gradually research became more
quantitative (Crust & Clough, 2005; Gucciardi, 2009; Hagag & Ali,
2014; Ponnusamy, Lines, Zhang, & Gucciardi, 2017;
Weissensteiner et al., 2012), which mainly used mental
toughness questionnaires and in other occasions questionnaires
containing some of the multiple characteristics or attributes
within the umbrella of mental toughness (Guillén & Laborde,
2014; Laborde, Guillén & Mosley, 2016; Laborde, Guillén, Watson
& Allen, 2017).
Qualitative studies attempted to develop a knowledge base in
the field of mental toughness, however, in most cases; they
resulted in replicates of previous findings. (Anthony, Gucciardi &
Gordon, 2016; Fourie & Potgeiter, 2001; Jones et al., 2002).
Furthermore, these studies focused excessively on elite
performers and assumed that super elite performers (Gold
Olympic or world medal holders) are mentally tougher than elite
athletes (silver medal holders). In this sense, Jones
and Moorhouse (2007) claimed that athletes who were mentally
tough were “better” when they have to face challenging
circumstances; however, this is problematic given that these
researchers failed to compare with athletes who were less
successful or mentally tough. Although it seems reasonable to
assume that mentally tougher athletes face challenging
circumstances better, it is evident that the descriptive nature of
most of the literature on mental toughness has not, to date,
proved to be satisfactory. This may be questionable if the other
multiple factors that determine success are taken into
consideration. In any case, the assumption that mental
toughness is the key factor to success or the differential factor
among the greatest soccer players is still speculation. For this
reason, further comparative studies are required in this field
although in order to do this, instruments with adequate
psychometric properties are necessary. (Crust, 2008; Gucciardi
et al., 2008).
The Psychological Performance Inventory (PPI; Loehr, 1986),
which consisted of 42 items, was most probably the first
instrument to measure mental toughness, however, it was
theoretically and conceptually limited. Golby, Sheard, & van
Wersch, (2007) highlighted its psychometric limitations to such
an extent that the proposal of seven factors received no support.
Later, Gucciardi (2012) also expressed his concerns in terms of
the conceptual and methodological problems of the PPI and the
PPI-A.

Exploring mental toughness in soccer players of different levels of performance
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº 2 (2018)
299
After nearly a decade, at the beginning of this century, a new
race to develop instruments to measure mental toughness
emerged.
One of the first instruments was the Mental Toughness
Questionnaire 48 (MTQ 48; Clough, Earle, & Sewell, 2002). This
was a 48-item questionnaire that not only offers an overall score
but also scores for each of the sub dimensions, commitment,
emotional control, life control, challenge, interpersonal
confidence and confidence in abilities. However, its factorial
structure has been questioned. (Gucciardi, 2017b; Gucciardi,
Hanton y Mallett, 2012).
The Mental Toughness Inventory (MTI; Middleton et al., 2004)
is an instrument consisting of 67 items that provide information
about the overall score and the score of 12 components of
mental toughness.
The Mental Toughness Questionnaire (MTQ), by Cherry (2005)
is an 18-item questionnaire designed to evaluate an individual's
competitive desire, focus, self-confidence, and resiliency.
The Mental, Emotional, and Bodily Toughness Inventory
(MeBTough; Mack, & Ragan (2008) is a questionnaire that has not
been widely used. It initially consisted of 45 items but was later
reduced to 43 items.
Immediately after, the Sports Mental Toughness
Questionnaire (SMTQ; Sheard, Golby & van Wersch, 2009) was
developed. It consisted of 14 items and three factors
(Confidence, Constancy, and Control).
Later, Madrigal, Hamill & Gill (2013) developed the Mental
Toughness Scale (MTS), which initially consisted of 54 items but
was later reduced to 11 items.
The Mental Toughness Factors in Sport (IMTF-S) by Stonkus &
Royal (2015), which was published recently, consists of 40 items
and covers four subdimensions (Motivation, Identification,
challenge and Determination) each of which contain 10 items.
Simultaneously, the Mental Toughness Index (MTI; Gucciardi
et al., 2015) was also published. It is the shortest of the existent
questionnaires with only 8 items
Lastly, Vaughan, Hanna & Breslin (2018) developed an
abbreviated version of the MTQ48, specifically, Mental
Toughness Questionnaire 18 (MTQ18)
Given that the study of mental toughness is relatively recent,
only two decades, there is not a lot of literature on this topic,
nonetheless, the multiple instruments that have been created to
measure it is outstanding. The scarcity of literature and
abundancy of instruments may possibly be the reason why
results are not consistent.
Hence, the need for further research in this area is evident,
using the existent instruments and employing adequate
psychometric properties.
The purpose of this study was to compare mental toughness
in young soccer players from an early age and with different
levels of performance. The aim was, on the one hand, to study
mental toughness at a very young age on the basis of their level
of performance. On the other hand, the aim was to contrast the
assessment in young athletes of two different age groups.
METHOD
Participants
The participants were 242 soccer players, 117 played for la Unión
Deportiva Las Palmas and 125 were players from other teams on
the island of Gran Canaria, mean age was 16.38 (DT = 1.38),
ranging from 14 to 19 years of age, they participated in the
categories under 16s (n = 99) and under19s (n = 143). This sample
consisted of men who played soccer at least four times a week
for a federated team. The players of UD Las Palmas, within the
different categories, under 16s and under 19s held the first
position of their category. In the final classification, the players
of the other teams who participated were in the second or third
position of their corresponding categories.
Instruments
This study was conducted using a sociodemographic
questionnaire which provided information on gender, age,
category, position played and the team in which they played.
Likewise, the Mental Toughness Index (Gucciardi, Hanton,
Gordon, Mallett, & Temby, 2015) was used. An example of one of
the 8 items of this questionnaire would be: “I believe in my ability
to achieve my goals”. Participants respond to each item on a 7-
point scale where 1-4 corresponds to “totally false” and 4-7 is
“totally true”. The score for reliability in the questionnaire
presented in this study was .78. It was translated in accordance
with the parallel back-translation method proposed by (Brislin,
1986). It was translated from English to Spanish and then
translated to English by another expert. They were then
compared by psychologists to verify that the items contained the
same meaning.
Finally, the players were asked three direct questions which
were to be answered on a scale of 1 to 10, do you believe in your
ability to play in a superior category? Do you believe in your
ability to play for your country? Can you see yourself playing for
a team of the First Division?
Procedure
The objectives of the study were explained to the participants
who were offered to participate voluntarily. The parents or
guardians of the underage participants were asked to sign
informed consent and authorization forms. The tests were
performed by one of the authors of the present study prior to
the training sessions.
Statistical analysis
The data obtained was analyzed using IBM SPSS Statistics 23 for
Windows 10.
Normality and homoscedasticity of the variables was verified
prior to the analysis.
A descriptive analysis was performed on the construct of
mental toughness using the Mental Toughness Index (MTI), as
well as three items that cover self-perception of level of
capability. The descriptive analysis calculated the typical
deviations and mean of the players as a whole. Afterwards, the
mean differences of those aspects were calculated according to
the category of the participants, according to the team and
according to the position they played in. Finally, a correlation
study was performed for age, the three questions posed and the
MTI.
The effect was calculated following the suggestions of Kline
(1998), who advised calculating Cohen’s d effect size to obtain the
effect-size index for the latent mean differences. The effect size
between the score obtained for the overall MTI and the level of

Félix Guillén & Jorge Santana
300
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº2 (2018)
the team is large (0.66), whereas the effect size in the overall MTI
and the category are small and below the minimum size effect
recommended by Cohen (Cohen, 1988)
RESULTS
As shown in table 1, differences have been found between both
categories, under 16s and under 19s, for the scale and the three
questions posed. Significant differences can also be observed in
the overall score of MTI although the effect size was small (d =
0.17), among the under 16 and under 19 soccer players and also
in regard to the question do you believe in your ability to play in a
superior category? (p = .000). No significant differences were
observed among the players of UD Las Palmas, however, there
were significant differences among the players of the other
teams (t = -2.60; p = .010) among the under 16s (M = 5.50; DT =
0.67) and the under 19s (M = 5.83; DT = 0.72).
Table 1
Descriptive analysis and mean differences of MTI and the questions posed, according to categories
General
N = 242
UNDER 16s
n = 99
UNDER 19s
n = 143
M (DT)
M (DT)
M (DT)
t
p
MTI
5.90 (.667)
5.78 (.698)
5.98 (.634)
-2.331
.023
To play in a superior category
8.83 (1.52)
8.37 (1.78)
9.14 (1.22)
-3.964
.000
To play for your country
7.29 (2.38)
7.13 (2.52)
7.39 (2.28)
-.835
.404
First Division team
7.48 (2.50)
7.37 (2.58)
7.55 (2.45)
-.546
.566
As shown in Table 2, mean differences are present in both team
groups, on the one hand UD Las Palmas and, on the other hand,
the other teams on the island of Gran Canaria that play in the
same category. Significant differences can be observed for
mental toughness using the MTI with a large effect size (d = 0.66)
and in two of the questions posed, the ability to play for your
country (p = .000) and seeing yourself playing for a team of the
First Division (p = .000).
When considered individually, significant differences were
found among the under 16 soccer players (t = 4.49; p = .000)
among the players of UD Las Palmas (M = 6.07; DT = 0.60) and the
players of the other teams (M = 5.50; DT = 0.67). Significant
differences were also found among the under 19 soccer players
(t = 3.13; p = .002) among the players of UD Las Palmas (M = 6.15;
DT = 0.47) and the players of the other teams (M = 5.83; DT = 0.72).
Table 2
Mean differences of MTI and the questions posed, according to the team they belong to
UD LAS PALMAS
n = 117
OTHER
n = 125
M (DT)
M (DT)
t
p
MTI
6.12 (.530)
5.70 (.717)
5.183
.000
To play in a superior category
8.97 (1.27)
8.69 (1.71)
1.466
.144
To play for your country
8.18 (1.90)
6.45 (2.48)
6.055
.000
First Division team
8.37 (1.65)
6.65 (2.85)
5.679
.000
As shown in Table 3, correlations of age, MTI and the questions
posed were found. Positive correlations were observed between
age and MTI, and the ability to play in a superior category.
Moreover, positive correlations were also found between MTI
and the perception the young players have of their ability to play
for their country or a 1st Division team.
Table 3
Correlations of age, MTI and questions posed to the players
1
2
3
4
5
Age
1
.166**
.240***
.110
.095
MTI
1
.420***
.538***
.524***
Superior Cat.
1
.587***
.626***
Country
1
.812***
1st Division
1
Note: *p < .05; **p < .01; ***p < .001
DISCUSSION
To date, there is very little literature on mental toughness in
young male soccer players, specifically under 19s. Consequently,
the purpose of this study was to acknowledge the existence of
possible differences in mental toughness among soccer players
of teams of different levels of performance.
For this reason, the participants chosen were, on the one hand,
soccer players from lower levels of the Spanish 1st division team,
all of which were in the first position of their category in the
championship classification, and on the other hand, soccer
players in teams belonging to the same category but in a lower
position.
We considered that it was especially interesting to study
mental toughness in adolescence, and for this reason we chose
soccer players in the categories of under and under 16s and
under 19s. The reason these categories were chosen was to
verify if differences could be observed at this age if you already
from these ages were appreciated differences in mental
strength.
Furthermore, this study has provided two nouvelle aspects in
relation to age. One of which is related to differences in mental
toughness according to age and, the other is that the subjects of
the study are young. Cowden (2017) mentioned in a recent study
that only four studies have been conducted with subjects
between 14 and 18 years old.

Exploring mental toughness in soccer players of different levels of performance
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº 2 (2018)
301
The results obtained in the study show greater mental
toughness in under 19 players tan in the under 16 players,
although the effect size was small. The results obtained in
previous research by Connaughton et al. (2008) appear to
confirm this assumption. Nevertheless, and despite scarce
literature which considers age, there is sufficient evidence that
indicates that older subjects show more mental toughness
(Dress & Mack, 2012; Gucciardi, Peeling, Ducker, & Dawson,
2016, Zeiger & Zeiger, 2018), which may be due to experience,
given that older athletes have more years of experience in sport
or it could also be related to biological changes in individuals.
The manner in which the level of performance has been
considered varies, for instance, in some occasions it was
considered according to the level of the athletes, international or
national, in other occasions depending on whether they were
amateurs or professional. In these cases, the contrast is
substantial, which favors the detection of differences. However,
in this study, we considered that it was more appropriate to
consider the team's position in the classification, as well as
belonging to an elite team, which implies social recognition. We
believe this perspective equals the participants and focuses
solely on the position obtained and the recognition that being
part of a great team entails.
Given their level of performance and as members of the most
representative team of their region, the players of UD Las Palmas
showed higher levels of mental toughness than players from the
other teams who obtained a lower position, and in turn, less
social recognition. This is consistent with the findings by
Danielsen, Rodahl, Giske, & Hnigaard (2017) in Norwegian soccer
players who responded to the SMTQ. Significantly higher scores
in MT were found in 1st division players than in 3rd division
players. However, no differences were found between the 1st
and 2nd division or between 2nd and 3rd division. However, no
differences were found between the 1st and 2nd division players
or between 2nd and 3rd division players. These findings also
coincide with those obtained in other studies, although other
instruments were used (Connaughton & Hanton, 2009; Elemiri &
Aly, 2014; Golby & Sheard, 2004; Gucciardi & Gordon, 2011;
Mohammadzadeh, Boostani & Boostani, 2009; Shin & Lee, 1994).
Another contribution of the present study is the use of a
questionnaire of mental toughness questionnaire such as the
Mental Toughness Index (MTI) in soccer, as this questionnaire
has been used very little given its recent creation. One of the
major problems in the study of mental toughness has been the
variety of instruments used (Cowden, 2017), which has possibly
led to the inconsistency of the results.
One of the limitations of this study is the size of the sample
which, although it was not small, could have preferably been
larger. Another obvious limitation is that this study was
conducted solely with male athletes. The transversal nature of
the study was also another important limitation. Undoubtedly,
longitudinal studies could offer enlightening information on the
influence of mental toughness.
A lot of research is still needed in the field of mental toughness
in sports, whether it is on individual or team sports, risk or
combat sports, etc. but it should also be related to multiple
variables that may condition mental toughness, favorably or not.
REFERENCES
Anthony, D., Gucciardi, D., & Gordon, S. (2016). A meta-study of
qualitative research on mental toughness development.
International Review of Sport & Exercise Psychology, 9, 160-190.
Bull, S. J., Shambrook, C. J., James, W., & Brooks, J. E. (2005).
Towards an understanding of mental toughness in elite
English cricketers. Journal of Applied Sport Psychology, 17,
209-227.
Cherry, H. L. (2005). Psychometric analysis of an inventory assessing
mental toughness (Unpublished master thesis). University of
Tennessee, Knoxville.
Clough, P. J., Earle, K., & Sewell, D. (2002). Mental toughness: The
concept and its measurement. En I. Cockerill (Ed.), Solutions
in sport psychology (pp. 32-43). Londres: Thomson
Cohen, D. (1988). Statistical power analysis for behavioral sciences.
Hillsdale: Erlbaum.
Coulter, T., Mallett, C. J., & Gucciardi, D. F. (2010). Comprender la
dureza mental en el fútbol australiano: percepciones de
jugadores, padres y entrenadores. Journal of Sports
Sciences, 28, 699-716.
Connaughton, D., Wadey, R., Hanton, S., & Jones, G. (2008). The
development and maintenance of mental toughness:
Perceptions of elite performers. Journal of Sport Sciences,
26(1), 83-95.
Cowden, R. G. (2017). Mental Toughness and Success in Sport: A
Review and Prospect. The Open Sports Sciences Journal, 10, 1-
14. doi: 10.2174/1875399X01710010001
Crust, L. (2008). A review and conceptual re-examination of
mental toughness: Implications for future researchers.
Personality and Individual Differences, 45(7), 576-583.
Crust, L. (2007). Mental toughness in sport: A review.
International Journal of Sport & Exercise Psychology, 5(3), 270-
290.
Crust, L., & Clough, P. J. (2005). Relationship between mental
toughness and physical endurance. Perceptual & Motor Skills,
100, 192-194.
Danielsen, L., Rodahl, S., Giske, R., & Hnigaard, R. (2017). Mental
toughness in elite and sub-elite female soccer players.
International Journal of Applied Sports Sciences, 29(19), 77-85.
Drees, M. J., & Mack, M. G. (2012). An Examination of Mental
Toughness over the Course of a Competitive Season. Journal
of Sport Behavior, 35(4), 377-386.
Elemiri, A., & Aly, A. (2014). Mental toughness and its relationship
to the achievement level of the weightlifters in Egypt. Turkish
Journal of Sport and Exercise, 16(2), 63-69.
doi:10.15314/TJSE.20142810
Ferguson, C. J. (2009). An effect size primer: A guide for clinicians
and researchers. Professional Psychology: Research and
Practice, 40(5), 532-538. doi:10.1037/a0015808
Fourie, S., & Potgieter, J. R. (2001). The nature of mental
toughness in sport. South African Journal for Research in Sport,
Physical Education and Recreation, 23, 63-72.
Golby, J., Sheard, M., & van Wersch, A. (2007). Evaluating the
factor structure of the psychological performance inventory.
Perceptual and Motor Skills, 105, 309-325.
Gould, D., Dieffenbach, K., & Moffett, A. (2002). Psychological
characteristics and their development in Olympic
champions. Journal of Applied Sport Psychology, 14, 172-204.

Félix Guillén & Jorge Santana
302
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº2 (2018)
Gucciardi, D. F. (2009). Do developmental differences in mental
toughness exist between specialized and invested
Australian footballers? Personality & Individual Diferences, 47,
985-989. doi:10.1016/j.paid.2009.08.001
Gucciardi, D. F. (2012). Measuring mental toughness in sport: A
psychometric examination of the Psychological
Performance Inventory-A and its predecessor. Journal of
Personality Assessment, 94, 393-403.
Gucciardi, D. F. (2017a). Mental toughness: progress and
prospects. Current Opinion in Psychology, 16, 17-23. doi:
10.1016/j.copsyc.2017.03.010
Gucciardi, D. F. (2017b). Commentary: Mental toughness and
individual differences in learning, educational and work
performance, psychological well-being, and personality: A
systematic review. Frontiers in Psychology, 8, 2329. doi:
10.3389/fpsyg.2017.02329
Gucciardi, D. F., y Gordon, S. (Eds.). (2011). Mental Toughness in
Sport: Developments in Theory and Research. Abingdon, Oxon:
Routledge.
Gucciardi, D. F., Gordon, S., & Dimmock, J. A. (2009). Evaluation of
a Mental Toughness Training Program for Youth-Aged
Australian Footballers: I. A Quantitative Analysis. Journal of
Applied Sport Psychology, 21, 307-323.
Gucciardi, D. F., Hanton, S., Gordon, S., Mallett, C. J., & Temby, P.
(2015). The concept of mental toughness: Tests of
dimensionality, nomological network and traitness. Journal
of Personality, 83(1), 26-44. doi:10.1111/jopy.12079
Gucciardi, D. F., Hanton, S., & Mallett, C. J. (2012). Progressing
measurement in mental toughness: A case example of the
Mental Toughness Questionnaire 48. Sport, Exercise and
Performance Psychology, 1, 194-214.
Gucciardi, D., Gordon, S., & Dimmock, J. (2008). Towards and
understanding of mental toughness in Australian football.
Journal of Applied Sport Psychology, 20, 261-281.
doi:10.1080/10413200801998556.
Gucciardi, D. F., Peeling, P., Ducker, K. J., & Dawson, B. (2016).
When the going gets tough: Mental toughness and its
relationship with behavioural perseverance. Journal of
Science and Medicine in Sport, 19(1), 81-86.
Guillén, F., & Laborde, S. (2014). Higher-order Structure of Mental
Toughness and the Analysis Latent Mean Differences
between athletes from 34 disciplines and non-
athletes. Personality & Individual Differences, 60, 30-35.
Hagag, H., & Ali, M. (2014). The relationship between mental
toughness and results of the Egyptian fencing team at the
9th All-Africa Games. Science, Movement and Health, 14, 85-
90.
Jones, G., & Moorhouse, A. (2007). Developing Mental Toughness
Gold Medal Strategies for Transforming your Business
Performance. Oxford, UK: Spring Hill.
Jones, G., Hanton, S., & Connaughton, D. (2002). What Is This
Thing Called Mental Toughness? An Investigation of Elite
Sport Performers. Journal of Applied Sport Psychology, 14,
205-218. doi:10.1080/10413200290103509
Jones, G., Hanton, S., & Connaughton, D. (2007). A framework of
mental toughness in the world's best performers. The Sport
Psychologist, 21(2), 243-264.
Kline, R. (1998). Principles and practice of structural equation
modeling. New York: Guilford.
Kuan, G., & Roy, J. (2007). Goal profiles, mental toughness and its
influence on performance outcomes among Wushu
athletes. Journal of Sports Science Medicine, 6, 28-33.
Laborde, S., Guillén, F., & Mosley, E. (2016). Positive personality
trait like individual differences in athletes from individual
and team sports and in non-athletes. Psychology of Sport &
Exercise, 26, 9-13.
Laborde, S., Guillén, F., Watson, M., & Allen, M. (2017). The light
quartet: positive personality traits and approaches to coping
in sport coaches. Psychology of Sport & Exercise, 32, 67-73.
Loehr, J. E. (1986). Mental toughness training for sport: achieving
athletic excellence. Lexington, MA: Stephen Greene.
Mack, M., & Ragan, B. (2008). Development of the mental,
emotional, and bodily toughness inventory in college
athletes and nonathletes. Journal of Athletic Training, 43, 125-
132. doi:10.4085/1062-6050-43.2.125.
Madrigal, L., Hamill, S., & Gill, D. L. (2013). Mind over matter: The
development of the Mental Toughness Scale (MTS). The Sport
Psychologist, 27(1), 62-77.
Middleton, S. C., Marsh, H. W., Martin, A. J., Richards, G. E., &
Perry, C. (2004). Discovering mental toughness: a qualitative
study of mental toughness in elite athletes. Self-Concept,
Motivation and Identity, Where to From Here?: Proceedings of
the Third International Biennial SELF Research Conference,
Berlin.
Ponnusamy, V., Lines, R. L. J. Zhang, C.-Q., & Gucciardi, D. F.
(2017). Latent profiles of elite Malaysian athletes’ use of
psychological skills and techniques and relations with
mental toughness. PeerJ, 6, e4778; doi:10.7717/peerj.4778
Sheard, M. (2010). Mental toughness: The mindset behind sporting
achievement. London, UK: Routledge.
Sheard, M., Golby, J., & van Wersch, A. (2009). Progress towards
Construct Validation of the Sports Mental Toughness
Questionnaire (SMTQ). European Journal of Psychological
Assessment, 25, 186-193. doi:10.1027/1015-5759.25.3.186
Shin, D. S., & Lee, K. H. (1994). A conparative study of mental
toughness between elite and non-elite female athletes.
Korean Journal of Sport Science, 6, 85-102.
Stajkovic, A. D. (2006). Development of a core confidence-higher
order construct. Journal of Applied Psychology, 91, 1208-1224.
Stonkus, M. A., & Royal, K. D. (2015). Further Validation of the
Inventory of Mental Toughness Factors in Sport (IMTF-S).
International Journal of Psychological Studies, 7(3), 35-45.
Suddaby, R. (2010). Editor’s comments: Construct clarity in
theories of management and organization. Academy of
Management Review, 35, 346-357.
Thelwell, R., Weston, N., & Greenlees, I. (2005). Defining and
understanding mental toughness within soccer. Journal of
Applied Sport Psychology, 17(4), 326-332. doi:
10.1080/10413200500313636
Vaughan, R., Hanna, D., & Breslin, G. (2018). Psychometric
properties of the Mental Toughness Questionnaire 48
(MTQ48) in elite, amateur and nonathletes. Sport, Exercise,
and Performance Psychology, 7(2), 128-140.
doi:10.1037/spy0000114
Weissensteiner J. R., Abernethy, B., Farrow, D., & Gross, J. (2012).
Distinguishing psychological characteristics of expert cricket
batsmen. Journal of Science and Medicine in Sport, 15(1), 74-
79. doi:10.1016/j.jsams.2011.07.003

Exploring mental toughness in soccer players of different levels of performance
Revista Iberoamericana de Psicología del Ejercicio y el Deporte. Vol. 13, nº 2 (2018)
303
Zeiger, J. S., & Zeiger, R. S. (2018). Mental toughness latent
profiles in endurance athletes. PLOS ONE 13(2), e0193071.