Are animal personality traits linked to life-history productivity?

Animal personality traits such as boldness, activity and aggressiveness have been described for many animal species. However, why some individuals are consistently bolder or more active than others, for example, is currently obscure. Given that life-history tradeoffs are common and known to promote inter-individual differences in behavior, we suggest that consistent individual differences in animal personality traits can be favored when those traits contribute to consistent individual differences in productivity (growth and/or fecundity). A survey of empirical studies indicates that boldness, activity and/or aggressiveness are positively related to food intake rates, productivity and other life-history traits in a wide range of taxa. Our conceptual framework sets the stage for a closer look at relationships between personality traits and life-history traits in animals.

Clarifying the effort-reward imbalance model : the role of personality

The thesis aimed to identify the sources of stress experienced by a sample of Australian police officers. It was guided by the Effort-Reward Imbalance model, augmented with Type A personality components. The findings support the research model and suggest that interventions to reduce stress should focus on reward and recognition.

The mediating role of work climate perceptions in the relationship between personality and performance

Although past research has demonstrated a link between personality and job performance, potential enabling factors of this relationship have yet to be explored comprehensively. We hypothesized that perceptions of work climate, specifically relationship dimensions—cohesion, supervisor support, and job involvement—might be the mechanism through which the relationship between personality and job performance can be explained. Two hundred and thirty Australian employees completed an online survey measuring personality, relationship dimensions of work climate (job involvement, coworker cohesion, and supervisor support) and job performance. Results revealed that the relationship dimensions of work climate fully mediated the relationship between agreeableness and job performance, and extraversion and job performance, while the relationship between neuroticism and job performance was partially mediated by relationship dimensions of work climate. Supervisor support primarily accounted for this mediated effect for the neuroticism–job performance relationship, whereas for extraversion only job involvement explained significant unique variance. Our findings suggest that the relationship of agreeableness, extraversion, and neuroticism with job performance is indirect, and perceptions of the work environment itself play a role in this relationship. This implies that organizations should consider the work environment, in addition to personality during selection procedures. Future research should examine whether different levels of work environment dimensions, foster greater job performance in employees.

Religious/spiritual well-being, coping styles and personality dimensions in people with substance use disorders

Religiosity and spirituality have been found to be negatively associated with a range of addictions. It has been suggested that religious/spiritual well-being might play an important role in the development, course and the recovery from addictive disorders. A sample of addiction in-patients (n=389) was assessed using the Multidimensional Inventory for Religious/Spiritual Well-Being (MI-RSWB) and compared with a matched group of non-addicted community controls (n=389). RSWB was found to be substantially lower in people with substance use disorders compared to the normal sample. Discriminate functional analysis showed that Experiences of Sense and Meaning, General Religiosity and Forgiveness were the dimensions of RSWB which strongly distinguished the groups. Within the group of people with substance use disorders, RSWB was strongly positively associated with the personality dimensions of Conscientiousness, Agreeableness and Openness as well as Sense of Coherence and positive Coping styles. The study suggests that therapeutic intervention programs focusing on building a positive and meaningful personal framework, akin to that of a religious/spiritual orientation, may contribute to positive outcomes in addiction treatment.

Performance, personality, and energetics : correlation, causation, and mechanism

The study of phenotypic evolution should be an integrative endeavor that combines different approaches and crosses disciplinary and phylogenetic boundaries to consider complex traits and organisms that historically have been studied in isolation from each other. Analyses of individual variation within populations can act to bridge studies focused at the levels of morphology, physiology, biochemistry, organismal performance, behavior, and life history. For example, the study of individual variation recently facilitated the integration of behavior into the concept of a pace-of-life syndrome and effectively linked the field of energetics with research on animal personality. Here, we illustrate how studies on the pace-of-life syndrome and the energetics of personality can be integrated within a physiology-performance-behavior-fitness paradigm that includes consideration of ecological context. We first introduce key concepts and definitions and then review the rapidly expanding literature on the links between energy metabolism and personality traits commonly studied in nonhuman animals (activity, exploration, boldness, aggressiveness, sociability). We highlight some empirical literature involving mammals and squamates that demonstrates how emerging fields can develop in rather disparate ways because of historical accidents and/or particularities of different kinds of organisms. We then briefly discuss potentially interesting avenues for future conceptual and empirical research in relation to motivation, intraindividual variation, and mechanisms underlying trait correlations. The integration of performance traits within the pace-of-life-syndrome concept has the potential to fill a logical gap between the context dependency of selection and how energetics and personality are expected to interrelate. Studies of how performance abilities and/or aspects of Darwinian fitness relate to both metabolic rate and personality traits are particularly lacking.

Personality and the emergence of the pace-of-life syndrome concept at the population level

The pace-of-life syndrome (POLS) hypothesis specifies that closely related species or populations experiencing different ecological conditions should differ in a suite of metabolic, hormonal and immunity traits that have coevolved with the life-history particularities related to these conditions. Surprisingly, two important dimensions of the POLS concept have been neglected: (i) despite increasing evidence for numerous connections between behavioural, physiological and life-history traits, behaviours have rarely been considered in the POLS yet; (ii) the POLS could easily be applied to the study of covariation among traits between individuals within a population. In this paper, we propose that consistent behavioural differences among individuals, or personality, covary with life history and physiological differences at the within-population, interpopulation and interspecific levels. We discuss how the POLS provides a heuristic framework in which personality studies can be integrated to address how variation in personality traits is maintained within populations.

The pace of life under artificial selection : personality, energy expenditure, and longevity are correlated in domestic dogs

The domestic dog has undergone extensive artificial selection resulting in an extreme diversity in body size, personality, life‐history, and metabolic traits among breeds. Here we tested whether proactive personalities (high levels of activity, boldness, and aggression) are related to a fast “pace of life” (high rates of growth, mortality, and energy expenditure). Data from the literature provide preliminary evidence that artificial selection on dogs (through domestication) generated variations in personality traits that are correlated with life histories and metabolism. We found that obedient (or docile, shy) breeds live longer than disobedient (or bold) ones and that aggressive breeds have higher energy needs than unaggressive ones. These correlations could result from either human preference for particular trait combinations or, more likely, correlated responses to artificial selection on personality. Our results suggest the existence of a general pace‐of‐life syndrome arising from the coevolution of personality, metabolic, and life‐history traits.

Energy metabolism and animal personality

In this paper we show how animal personality could explain some of the large inter-individual variation in resting metabolic rate (MR) and explore methodological and functional linkages between personality and energetics. Personality will introduce variability in resting MR measures because individuals consistently differ in their stress response, exploration or activity levels, all of which influence MR measurements made with respirometry and the doubly-labelled water technique. Physiologists try to exclude these behavioural influences from resting MR measurements, but animal personality research indicates that these attempts are unlikely to be successful. For example, because reactive animals “freeze” when submitted to a stress, their MR could be classified as “resting” because of immobility when in fact they are highly stressed with an elevated MR. More importantly, recent research demonstrating that behavioural responses to novel and highly artificial stimuli are correlated with both behaviour and fitness under more natural circumstances calls into question the wisdom of excluding these behavioural influences on MR measurements. The reason that intra-specific variation in resting MR are so weakly correlated with daily energy expenditure (DEE) and fitness, may be that the latter two measures fully incorporate personality while the former partially excludes its influence. Because activity, exploration, boldness and aggressiveness are energetically costly, personality and metabolism should be correlated and physiological constraints may underlie behavioural syndromes. We show how physiological ecologists can better examine behavioural linkages between personality and metabolism, as required to better understand the physiological correlates of personality and the evolutionary consequences of metabolic variability.