Motivation and emotion/Book/2021/Mental toughness

Mental toughness:
What is mental toughness, how does it help, and how can it be developed?

Overview

edit
 
Figure 1. Mental toughness in military training to hold the log and complete the task.

As a person navigates life, there will be times where complex achievement pursuit and challenges arise that require a combination of behavioural attributes and personality traits that assist in overcoming adversity. These may be required across a variety of settings, such as schooling endeavours, workplaces, sporting pursuits and the military (see Figure 1) (Gucciardi et al., 2014). Mental toughness (MT) is goal directed and reliant on psychological resources that an individual possesses (Gucciardi, 2017). Characterised by focus, flexibility, and efficiency, these factors by nature are a key component in the mechanisation [say what?] and upkeep required for positive goal-directed pursuits.

Mental toughness is displayed clearly in goal-directed endeavours comprising of proactive and reactive experiences that are accompanied by stressors of varying levels of intensity, frequency, and duration, depending on the environmental context (Crust & Clough, 2010). For example, an athlete who is preparing and planning for an event is undergoing a proactive mental toughness experience, whilst an athlete who gets injured during an event undergoes a reactive mental toughness experience.


Case Study - "Flu Game"

Michael Jordan of the Chicago Bulls succumbs to a severe flu during Game 6 of the 1998 NBA Finals where his team needs one more victory to secure the championship. Given the fact that they have worked all year to be in this position, Michael goes against medical advice and plays despite his condition. Although he is not in optimal circumstances, he perseveres due to the gravity of the situation, his individual motivation and team's goals, finding a way to contribute. Having previously missed the game winning shot in the match prior that allowed the opposing team to prevent elimination. Michael finds himself in the same situation after stealing the ball from the opposition, with the last shot of the game he shoots and scores a crucial go-ahead bucket that ultimately wins the game and championship. As the final buzzer rings, he slumps into his teammates arms to be assisted off the court after displaying one of the greatest displays of mental toughness in order to achieve the goal.[factual?]


Focus questions
  • What is mental toughness?
  • How does it help?
  • What is its role in motivation?

Definition of Mental Toughness

edit
 
Figure 2. Scientific method testing procedure.

[Provide more detail]

Early Conceptualisation

edit

Early theories that formed what is now accepted as the definition of mental toughness conceptualised the concept as a culturally or environmental personality trait that contributed an individual’s success (Catell et al., 1955). This remained the predominate[spelling?] theory for decades until the concept began to be further developed through a sporting lens. The most significant research development came from Loehr (1982), who found key determinants in elite athlete success from surveys of athletes and coaches. The findings were that athletes believe around half of top levels of performance were attributed to psychological factors similar to mental toughness. Furthermore, [missing something?] majority of coaches found it as a key determinant in competitive success. These results, coupled with additional research conducted by Loehr led to the first model of mental toughness being published in 1986.

Although early research was found to lack rigorous scientific and theoretical methods (see Figure 2), the conceptualisation and research conducted set the foundation for modern research. Future research in this area aims to address the lack of conceptual clarity in regards to what constitutes mental toughness and to clarify the ambiguity of existing definitions. In order to address methodological and substantive issues that have arisen in previous conceptualisation processes, empirically supported scales have been developed to substantiate the concept. A clear definition of mental toughness is still debated, however the generally accepted definition is: Mental toughness is a trait that comprises of individual resilience and self-belief that positively affects goal-directed pursuits that can predict success across a wide range of settings[factual?].

Measurement Scales

edit

Although there have been numerous developments of mental toughness scales not all make as significant contribution as others, therefore, a brief summary and explanation of the most prevalent are listed in the table below:

Scale Properties
Psychological Performance Inventory (PPI)
  • In addition to using a 42-item overall mental toughness score, the PPI contains seven 7-item subscale scores: self-confidence, negative energy control, attention control, visualization and imagery control, motivation, positive energy, and attitude control (Loehr, 1986).
  • Although the scale was published with no information on item development procedures or psychometric data to support its reliability and validity. Evidence to support internal consistency was found (Middleton et al., 2004).
Psychological Performance Inventory Alternative (PPI-A)
  • Is a revised version of the original PPI scale that implements a 14-item overall mental toughness score, that contains four subscale scores: determination, self-belief, positive control, and visualization (Golby, 2007). The psychometric properties of the PPI-A have preliminary support for validity (Golby et al., 2007).
Mental Toughness Questionnaire (MTQ48)
  • Is one of the most widely used scales to measure mental toughness. It assesses overall mental toughness and consists of four dimensions: Challenge, commitment, confidence and control, which is referred to as the 4C's of mental toughness (Clough, 2002).
  • This scale is one of the most refined scales psychometrically and has high internal and test-retest reliability (Crust, 2009; Gerber et al., 2015, 2018). Furthermore Horsburgh et al., (2009) found validity of the factorial structure and thus, is one of the most commonly used scales to measure mental toughness.
  • Current research by Dagnall et al., (2019) is investigating the validity of a reduced format of the MTQ-18 and the MTQ-10. Overall, analysis indicated that the MTQ-10 was a psychometrically superior global measure to the MTQ-18. Future research in the area must address temporal stability of the scales and test-retest reliability.
Mental Toughness Inventory (MTI)
  • Is a 67-item self report paper that assesses 12 characteristics of mental toughness. These factors consist of: self-efficacy, potential, mental self-concept, task familiarity, value, personal bests, goal commitment, perseverance, task focus, positivity, stress minimisation, and positive comparisons (Middleton et al., 2005).
  • This scale has validity within an elite athlete sample and strong psychometric properties due to a high reliability coefficients and acceptable goodness of fit for the confirmatory factor analysis.
Mental, Emotional, and Bodily Toughness Inventory (MeBTough)
  • Is a 43-item scale that assesses the mental, emotional and physical toughness of an individual (Mack & Ragan, 2008). Overall, Rasch model assess that the scale has good psychometric properties and in comparison with the majority of previously developed scales, it can discriminate among individuals along a wide ability range.
  • In a systemic review by Farnsworth et al., (2021), evaluating the current mental toughness measurement properties and scales. Only the MeBtough scale demonstrated acceptable values for all measurement properties, with the structural validity rated sufficient. The only other scale to show struct validity is the MTQ-18, but due to limited reliability data, future research must address.

Differentiation from other positively associated concepts

edit

[Provide more detail]

Resilience

edit

A similar construct that mental toughness is often used interchangeably with is resilience. Resilience is defined as the ability to adapt and respond positively both mentally and emotionally to any risk to normative function in an individual from external factors (Southwick et al., 2014). Enabling the adaptability to stressful experiences through specific behaviours and mental processes that safeguard from potential negative stressors[grammar?]. The differences between mental toughness and resilience are that MT is focused on the existing psychological resources of the individual, whereas resilience is applicable across groups, organisations, and ecosystems (Gucciardi, 2017). Additionally, protective factors arise such as biological factors, social support networks and societal dimensions, once again differing to MT as it is solely focused on an individual’s psychological resources. Lastly, resilience is predominately reactive and hinges on the individual’s adaptability in the face of adversity or challenging situations. In contrast, MT is centred around goal-directed ventures, focusing on proactive and reactive experiences (Gucciardi, 2017).

Grit

edit

Another concept that aligns closely with mental toughness is grit, which is defined as having passion and perseverance for goals that are long term. The passion for set goals enables perseverance and diligence when faced with potential negative stressors and is conceptualised as a component of the Big Five factors of conscientiousness (Gucciardi, 2017).There are differences between mental toughness and grit, irrespective of the goal-directed nature of the constructs. Grit is defined as conceptually dispositional and reflects an individual’s consistency, quality of character, habits and predisposed behavioural actions in pursuit of a singular goal (see Figure 3) across a wide range of situations and time (Duckworth et al., 2007). Juxtaposed with MT, that [what?] is unique to each individual and influenced environmentally, contextually and over time. This [which?] construct also has enduring properties that can vary dependent on the demands contextually and that of the goals. Additionally, the definition of what a goal is varies between the constructs as MT goal-direction focus is across multiple, varying levels of goals (Eskreis-Winkler et al., 2016) In comparison with grit, that is focused primarily on a single focused goal and the steps required to achieve it[grammar?].

Hardiness

edit

Although they share some similar conceptual foundations, there is a distinct difference between [which?] the concepts. Originally defined as a personality structure that consists of commitment, control and challenge factors, it was conceptualized as an individual's ability to resist stress (Kobasa, 1979). The difference between the concepts is that individuals who score high on MT scales are able to remain consistent[grammar?] goal-focused when stressors arise. Confidence and intrinsic self-belief enable the individual to continue striving towards completing the task and show assertiveness in social situations (Lin et al., 2017).


 
Quiz

Mental toughness is a trait that comprises of individual resilience and self-belief that positively affects goal-directed pursuits that can predict success across a wide range of settings:

True
False

How Does it Help?

edit

[Provide more detail]

Goal achievement

edit
 
Figure 4. Big 5 factors of personality model.

Throughout a vast number of contextual settings such as academic, workplace and athletic pursuits, mental toughness is positively associated with high levels of performance in competitive situations. In conjunction with aspects of the Big Five factors (see Figure 4), mental toughness was found to be a vital resource in addressing challenges and obstacles that arise in academic pursuits (Lin et al., 2017). A trait that conveys a high level of coping skills and adaptation to each task[grammar?]. A study that sampled school performance levels amongst adolescents found a positive correlation between mental toughness, academic attainment, and attendance, measured on the 4C’s[grammar?] model (St Clair-Thompson et al., 2014).

Similarly, these findings translate to the workplace environment, where career advancement and higher levels of management positions were found to be closely associated with mental toughness (Gucciardi et al., 2015). Furthermore, the results found that perceived stress, which is found to be lower in individuals with higher mental toughness, was positively correlated with higher levels of work performance[say what?]. In a martial arts combat athlete sample, mental toughness was positively associated in successful performance outcomes, such as medalling at a championship tournament[factual?].

A Psychological Performance Inventory (PPI) was used to assess the correlation between goal profiles, mental toughness, and performance outcomes of the [which?] athletes. Results found significant effects of mental toughness in goal achievement and a higher prevalence of mental resources in mentally tough athletes leading to more success (Kuan & Roy, 2007). Furthermore, participants with higher task focus showed more mastery and competence with their skillset, with more successful performers displaying greater mental toughness. Higher levels of mental toughness were found in individuals who were medallists, in comparison to non-medallists.

The aforementioned evidence suggests that mental toughness plays a significant role in goal achievement across a diverse range of competitive scenarios.

Behavioural influence

edit

Mental toughness has shown to not only influence performance outcomes, but also in behavioural aspects such as promoting motivation, perseverance, and self-efficacy (Gucciardi, 2010). The positive association with these factors and MT means that any changes in a factor may cause an imbalance that implicates goal achievement.

 
Figure 5. Runners displaying perseverance to finish marathon and cross the line.

A large sample of adolescent male Australian footballers were measured on a self-reported MT and behavioural persistence through a shuttle run test. Results found a positive correlation between MT and perseverance which influenced the level achieved in the test. Furthermore, the findings support the notion that persistence and perseverance is a key behavioural indicator of mentally tough athletes.[factual?]

The findings of the previous study were replicated in a repeated measures design study that incorporated a fatigue inducing activity one week after the initial testing. Results of this research found mental toughness was positively correlated with perseverance, however, the factors didn’t not find the same significance in performance outcomes when participants were under fatigue (Giles et al., 2018). Thus, strengthening the validity of MT and perseverance as a positive factor in behavioural influence and goal pursuits (see Figure 5)[grammar?]. Future research in this area would benefit from a more generalisable sample.

A recent study of what fosters behavioural perseverance in highly stressful circumstances where no feedback about goal achievement progress is given, was conducted. The purpose was to assess the efficacy of MT as a key determinant of behavioural perseverance in arduous and complex situations across an extended period of time. The sample was Canadian Special Forces Selection course participants who were attempting to pass selection, who also undertook a MT assessment and a hair cortisol measurement before and after the course.[factual?]

The findings replicated previous studies results but in particular, found that a one-unit increase in mental toughness scale would indicate a 68% increase in the odds of selection (Gucciardi et al., 2021). Furthermore, the findings incorporated [say what?] with a biological marker for accumulated stress, further support the validity of mental toughness[grammar?]. As a salient factor for behavioural perseverance in high stress environments, across a variety of tasks and over a long period[grammar?].

Mental health outcomes

edit

Mental toughness is an effective protective factor against a number of mental health conditions and negative physiological outcomes. A wide variety of studies have been conducted over a range of social groups that support the validity of the concept. One study sampled a group of middle eastern medical students using the MTQ48 scale and found that participants with a higher mental toughness scores reported fewer incidences of anxiety, burnout, and insomnia symptoms, irrespective of stress levels (Haghighi & Gerber, 2019). Evidence suggests that mental toughness is positively associated with lower depressive, stress, and anxiety levels. Whilst finding that physiologically, individuals are less likely to suffer from insomnia and burnout[grammar?].

These findings were replicated in a young elite athlete sample using the MTQ48, with the results indicating that athletes with higher levels of mental toughness scores were found to have significantly fewer mental health issues that arise in high stress exposure situations (Gerber et al., 2018)

A meta-analytic review of the empirical studies assessed the validity of mental toughness associations across a range of positive work, psychological and personality factors[factual?]. Findings indicate that it is a vital attribute that individuals who possess a high level are more emotionally stable and have better ability to maintain and control any threats that may negatively impact them under stressful conditions (Lin et al., 2017). This supports MT as a protective factor that enables better psychological well-being through effective coping strategies and has shown to enable positive achievement outcomes.


 
Quiz

Mental toughness is not beneficial in goal-pursuit:

True
False

How Mental Toughness is Developed

edit

[Provide more detail]

Scientific theory

edit

Although there has been a number of studies conducted regarding mental toughness, there is an apparent need for more theoretically driven research to be conducted with more scientific methodology. There have been two main psychologically based theories that have been used to try and provide more researched based support for the concept.

Personal Construct Psychology Theory

edit

One major investigation into this area came through the applicability of Personal Construct Psychology (PCP) with mental toughness in an attempt to further research that is established in psychological theory. PCP is focused on how an individual's interpretation of events and occurrences in their environment dictate the behavioural reaction is in response (Kelly, 1955). Compared with other theoretical frameworks that are concerned solely on single functions, PCP is focused on a combination of components such as motivation, values, emotion and cognition, being combined into one concept. The concept has a base of a large amount of empirical support across a wide range of professions and practical applications and thus, provide a clearer understanding of mental toughness in sport if researched from this perspective. Gucciardi et al. (2009) assessed the applicability of the theory in explaining aspects of mental toughness. Research findings proposed that enhancement in understanding would be made upon an adoption of a PCP perspective in mental insight through greater insight into greater understanding of MT and conceptual opposites, why certain events demand MT from athletes, what drives an athlete to be mentally tough in these events and what comes of the MT process.[vague][for example?]

 
Figure 6. A model of DNA, which has shown to play a role in mental toughness traits.

Self-Determination Theory

edit

Another major investigation into integration of the understanding of mental toughness with established psychological theory was self-determination theory (SDT). SDT is focused on human motivation and the degree to which individuals actions are chosen freely in comparison to controlled (Deci & Ryan, 2018). Based upon three psychological needs: autonomy, competence and relatedness, which when satisfied predict the extent that an individual will grow psychologically[grammar?]. This growth is also factors [grammar?] in the environment of the individual and if it is nurturing or constricting of development.

Maloney et al. (2014), assessed the validity of the theory in explaining aspects of mental toughness. Research findings proposed that autonomy-supportive environments and positively influence mental toughness development through the needs satisfaction and autonomous goal-striving[grammar?]. Whereas controlling environments stunts development through undermining and dismissing the importance of an individuals psychological needs and goal-striving desire[grammar?]. The focus of the [which?] study in bridging the conceptual gap between mental toughness and SDT is on striving, surviving and thriving.

Genetic component

edit

In regard to the genetic heritability of mental toughness, there have been a small sample of studies that have explored its influence. The first investigation into mental toughness and Big Five personality traits at the genetic and environmental level was conducted by Horsburgh et al. (2009), that sampled 219 adult twins[grammar?]. The results found that the heritability for mental toughness accounted for 52% of the variance, with the remaining 48% accounted for by environmental factors. These findings support the notion that genetic[grammar?] do play a significant role in mental toughness as a trait, the reliability of the results may be questionable due to the methodology of data collection and lack of scientific rigidity[grammar?].

Further investigation was conducted by Veselka et al. (2009) to assess if mental toughness and emotional intelligence could be integrated into a general factor of personality. A twin sample was used to assess heritability and the results found that significance between the Big Five factors and the four scales of mental toughness (Veselka et al., 2009). Furthermore, individual differences were accounted for by genetic and environmental factors, a result replicated in previous studies. Which adds validity to the notion that mental toughness and personality factors are highly heritable in a twin sample[grammar?].

Environmental influence

edit
 
Figure 7. Two individuals playing the same game with different goal motivation.

Environmental influences have shown to have as much effect in mental toughness traits as genetic factors (see Figure 6). Therefore, exploration into what defines these influences is required. A meta-analysis investigating research journals over a 10-year period found that mental toughness is influenced by internal and external factors (Aryanto & Larasati, 2020). The study defined internal factors as self-determined motivation, self-concept, self-insight, self-esteem, introspective reflection, characteristic adaptation, and competitive trait anxiety. With external factors defined as physical and mental training programs, coaching style, coach-athlete relationship, and communication style[grammar?]. Evidence suggests that these factors are a key determinant of athlete’s[grammar?] level of mental toughness in goal achieving pursuits and build upon an athlete’s genetic heritability level of the trait (Anthony et al., 2016).

Influences outside of the direct athlete’s training network and competitive environment have shown to be a factor in affecting mental toughness (Bull et al., 2005). A sample of cricketers was used to assess the influence that parent’s attitude toward failure or achievement affected the view of performance, leading to negative association with criticism and thus, stunting progression. Researchers suggested that removal of external influences may allow the athlete to focus solely on the performance (Bull et al., 2005). This finding of external factors and incidents that occur throughout the process, being positive or negative, have a significant effect on an individual’s mental toughness (Connaughton et al., 2010). Thus, highlighting the significance that environmental factors (see Figure 7) have in the role of mental toughness[grammar?].

Conclusion

edit

Mental toughness is a trait that can positively impact an individual's ability to complete a task to the best of their ability and assist in remaining goal-oriented in the onset of stressors. It assists in maintaining focus and to mitigate any potential negative impacts that may occur along the process, and can be genetically heritable or developed by a range of environmental factors. Although there has been many attempts at conceptualizing and defining mental toughness, clear definition and scientific validity remains an issue. Future research in this area would benefit from clarity of definition, conceptualisation, and incorporation of a more rigorous scientific approach (Crust, 2008). This would address major concept concerns and assist in differentiating from other positively associated constructs within the field of psychology.

The benefit of a more structured scientific framework would illustrate how it can play a role in settings external to athletic, workplace and military environments. Offering applicability of the concept across a more diverse range of environmental settings[grammar?]. Given its effectiveness in predicting success in these areas, further scientific understanding may help to benefit individual's pursuits in external domains. Mental toughness is a key factor in motivating an individual to achieve goals, irrespective of stressors that may arise during the pursuit. This would suggest that it plays a key role in motivation and success, therefore, future outcome potential on a fully formed concept and definition may be highly valuable across contexts.

See also

edit

References

edit
Anthony, D. R., Gucciardi, D. F., & Gordon, S. (2016). A meta-study of qualitative research on mental toughness development. International Review of Sport and Exercise Psychology, 9(1), 160–190. https://doi.org/10.1080/1750984X.2016.1146787

Aryanto, D. B., Larasati, A. (2020). Factors Influencing Mental Toughness. Proceedings of the 5th ASEAN Conference on Psychology, Counselling, and Humanities (ACPCH 2019), 307-309. https://doi.org/10.2991/assehr.k.200120.066

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(3), 209–227. https://doi.org/10.1080/10413200591010085

Cattell, R. B., Blewett, D. B., & Beloff, J. R. (1955). The inheritance of personality; a multiple variance analysis determination of approximate nature-nurture ratios for primary personality factors in Q-data. American Journal of Human Genetics, 7(2), 122–146.

Connaughton, D., Hanton, S., & Jones, G. (2010). The Development and Maintenance of Mental Toughness in the World’s Best Performers. The Sport Psychologist, 24(2), 168–193. https://doi.org/10.1123/tsp.24.2.168

Crust, L. (2008). A review and conceptual re-examination of mental toughness: Implications for future researchers. Personality and Individual Differences, 45(7), 576–583. https://doi.org/10.1016/j.paid.2008.07.005

Crust, L. (2009). The relationship between mental toughness and affect intensity. Personality and Individual Differences, 47(8), 959–963. https://doi.org/10.1016/j.paid.2009.07.023

Crust, L., & Clough, P. J. (2011). Developing Mental Toughness: From Research to Practice. Journal of Sport Psychology in Action, 2(1), 21–32. https://doi.org/10.1080/21520704.2011.563436

Dagnall, N., Denovan, A., Papageorgiou, K. A., Clough, P. J., Parker, A., & Drinkwater, K. G. (2019). Psychometric Assessment of Shortened Mental Toughness Questionnaires (MTQ): Factor Structure of the MTQ-18 and the MTQ-10. Frontiers in Psychology, 10, 1933–1933. https://doi.org/10.3389/fpsyg.2019.01933

Duckworth, A. L., Peterson, C., Matthews, M. D., & Kelly, D. R. (2007). Grit: Perseverance and Passion for Long-Term Goals. Journal of Personality and Social Psychology, 92(6), 1087–1101. https://doi.org/10.1037/0022-3514.92.6.1087

Eskreis-Winkler, L., Gross, J. J., & Duckworth, A. L. (2016). Grit: Sustained self-regulation in the service of superordinate goals. Handbook of self-regulation: Research, theory and applications (3rd ed), Guilford (2017), pp. 1-17

Farnsworth, J. L., Marshal, A., & Myers, N. L. (2021). Mental toughness measures: A systematic review of measurement properties for practitioners. Journal of Applied Sport Psychology, 1–16. https://doi.org/10.1080/10413200.2020.1866710

Gerber, M., Best, S., Meerstetter, F., Walter, M., Ludyga, S., Brand, S., Bianchi, R., Madigan, D. J., Isoard-Gautheur, S., & Gustafsson, H. (2018). Effects of stress and mental toughness on burnout and depressive symptoms: A prospective study with young elite athletes. Journal of Science and Medicine in Sport, 21(12), 1200–1205. https://doi.org/10.1016/j.jsams.2018.05.018

Gerber, M., Lang, C., Feldmeth, A. K., Elliot, C., Brand, S., Holsboer-Trachsler, E., & Pühse, U. (2015). Burnout and Mental Health in Swiss Vocational Students: The Moderating Role of Physical Activity. Journal of Research on Adolescence, 25(1), 63–74. https://doi.org/10.1111/jora.12097

Giles, B., Goods, P. S., Warner, D. R., Quain, D., Peeling, P., Ducker, K. J., Dawson, B., & Gucciardi, D. F. (2018). Mental toughness and behavioural perseverance: A conceptual replication and extension. Journal of Science and Medicine in Sport, 21(6), 640–645. https://doi.org/10.1016/j.jsams.2017.10.036

Golby, J., Sheard, M., & Van Wersch, A. (2007). Evaluating the Factor Structure of the Psychological Performance Inventory. Perceptual and Motor Skills, 105(1), 309–325. https://doi.org/10.2466/pms.105.1.309-325

Gucciardi, D. F. (2010). Mental toughness profiles and their relations with achievement goals and sport motivation in adolescent Australian footballers. Journal of Sports Sciences, 28(6), 615–625. https://doi.org/10.1080/02640410903582792

Gucciardi, D. F. (2017). Mental toughness: progress and prospects. Current Opinion in Psychology, 16, 17–23. https://doi.org/10.1016/j.copsyc.2017.03.010

Gucciardi, D. F., Gordon, S., & Dimmock, J. A. (2009). Advancing mental toughness research and theory using personal construct psychology. International Review of Sport and Exercise Psychology, 2(1), 54–72. https://doi.org/10.1080/17509840802705938

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. https://doi.org/10.1111/jopy.12079

Gucciardi, D. F., Jackson, B., Hodge, K., Anthony, D. R., & Brooke, L. E. (2015). Implicit Theories of Mental Toughness: Relations With Cognitive, Motivational, and Behavioral Correlates. Sport, Exercise, and Performance Psychology, 4(2), 100–112. https://doi.org/10.1037/spy0000024

Gucciardi, D. F., Lines, R. L. J., Ducker, K. J., Peeling, P., Chapman, M. T., & Temby, P. (2021). Mental toughness as a psychological determinant of behavioral perseverance in special forces selection. Sport, Exercise, and Performance Psychology, 10(1), 164–175. https://doi.org/10.1037/spy0000208

Gucciardi, D. F., Peeling, P., Ducker, K. J., & Dawson, B. (2014). When the going gets tough: Mental toughness and its relationship with behavioural perseverance. Journal of Science and Medicine in Sport, 19(1), 81–86. https://doi.org/10.1016/j.jsams.2014.12.005

Haghighi, M., & Gerber, M. (2019). Does Mental Toughness Buffer the Relationship Between Perceived Stress, Depression, Burnout, Anxiety, and Sleep? International Journal of Stress Management, 26(3), 297–305. https://doi.org/10.1037/str0000106

Horsburgh, V. A., Schermer, J. A., Veselka, L., & Vernon, P. A. (2009). A behavioural genetic study of mental toughness and personality. Personality and Individual Differences, 46(2), 100–105. https://doi.org/10.1016/j.paid.2008.09.009

Kara, Ö. S., Büyüklüoğlu, G., Büyüklüoğlu, N., Gül, S., Mesut Çelebi, M., & Kaya, H. (2021). Professional athletes have higher anxiety levels during COVID-19 outbreak compared to recreational athletes and sedentary people. Spor Hekimliği Dergisi, 56(2), 73–80. https://doi.org/10.47447/tjsm.0502

Kelly, G. A. (1955). The psychology of personal constructs. Vol. 1. A theory of personality. Vol. 2. Clinical diagnosis and psychotherapy. W. W. Norton.

Kobasa, S. C. (1979). Stressful life events, personality, and health: An inquiry into hardiness. Journal of Personality and Social Psychology, 37(1), 1–11. https://doi.org/10.1037/0022-3514.37.1.1

Kuan, G., & Roy, J. (2007). Goal Profiles, Mental Toughness and its Influence on Performance Outcomes among Wushu Athletes. Journal of Sports Science & Medicine, 6(CSSI-2), 28–33.

Lin, Y., Mutz, J., Clough, P. J., & Papageorgiou, K. A. (2017). Mental Toughness and Individual Differences in Learning, Educational and Work Performance, Psychological Well-being, and Personality: A Systematic Review. Frontiers in Psychology, 8, 1345–1345. https://doi.org/10.3389/fpsyg.2017.01345

Loehr, J. (1982). Mental toughness training for sports: Achieving athletic excellence. Plume. Mack, M. G., & Ragan, B. G. (2008). Development of the mental, emotional, and bodily toughness inventory in collegiate athletes and nonathletes. Journal of Athletic Training, 43(2), 125–132. https://doi.org/10.4085/1062-6050-43.2.125

Mahoney, J., Ntoumanis, N., Mallett, C., & Gucciardi, D. (2014). The motivational antecedents of the development of mental toughness: a self-determination theory perspective. International Review of Sport and Exercise Psychology, 7(1), 184–197. https://doi.org/10.1080/1750984X.2014.925951

Middleton, S. C., Marsh, H. W., Martin, A. J., Richards, G. E., Savis, J., Perry Jr, C., & Brown, R. (2004). The Psychological Performance Inventory: Is the mental toughness test tough enough? International Journal of Sport Psychology. 35: 91–108.

Middleton, S. C., Marsh, H. W., Martin, A. J., Richards, G. E., & Perry, C. (2005). Developing a test for mental toughness: The Mental Toughness Inventory (MTI). In Australian Association for Research in Education 2005 conference papers.

Ryan, R. M., & Deci, E. L. (2018). Self-determination theory: basic psychological needs in motivation, development, and wellness. The Guildford Press.

St Clair-Thompson, H., Bugler, M., Robinson, J., Clough, P., McGeown, S. P., & Perry, J. (2015). Mental toughness in education: exploring relationships with attainment, attendance, behaviour and peer relationships. Educational Psychology (Dorchester-on-Thames), 35(7), 886–907. https://doi.org/10.1080/01443410.2014.895294

Southwick, S. M., Bonanno, G. A., Masten, A. S., Panter-Brick, C., & Yehuda, R. (2014). Resilience definitions, theory, and challenges: interdisciplinary perspectives. European Journal of Psychotraumatology, 5(1), 25338–14. https://doi.org/10.3402/ejpt.v5.25338

Veselka, L., Schermer, J. A., Petrides, K. V., & Vernon, P. A. (2009). Evidence for a Heritable General Factor of Personality in Two Studies. Twin Research and Human Genetics, 12(3), 254–260. https://doi.org/10.1375/twin.12.3.254

edit