Plasticity in animal personality traits: does prior experience alter the degree of boldness?

Abstract

Theoreticians predict that animal 'personality' traits may be maladaptive if fixed throughout different contexts, so the present study aimed to test whether these traits are fixed or plastic. Rainbow trout (Onchorhyncus mykiss) were given emboldening or negative experiences in the forms of watching bold or shy individuals responding to novelty or winning or losing fights to examine whether prior experience affected boldness. Bold individuals that lost fights or watched shy demonstrators became more shy by increasing their latency to approach a novel object, whereas shy observers that watched bold demonstrators remained cautious and did not modify their responses to novelty. Shy winners became bolder and decreased their latency to approach a novel object, but shy losers also displayed this shift. In comparison, control groups showed no change in behaviour. Bold fishes given negative experiences reduced their boldness which may be an adaptive response; however, shy fishes may base their strategic decisions upon self-assessment of their relative competitive ability and increase their boldness in situations where getting to resources more quickly ensures they outcompete better competitors.

Are personality differences in a small iteroparous mammal maintained by a life-history trade-off?

“…an individual  age interaction [31]). Prior experience could increase boldness [39], leading to higher risk-taking behaviour in older males. Variation in individual male plasticity with age was high in all age classes, however, suggesting a cautious interpretation of the individual  age interaction.…”

Individual differences in metabolism predict coping styles in fish

“…It should be noted, however, that this plasticity seems to be context dependent. Frost et al (2007) for instance, showed that bold fish appear to be more flexible in changing their behaviour when observing other individuals with opposing personality traits, as compared to shy individuals.…”

“…Silva et al, 2010). In either case, the results suggest that active copers, as opposed to passive copers can be behaviourally characterised by (1) actively trying to escape from a stressor (Silva et al, 2010), (2) showing higher feed motivation after transfer to a new environment (Øverli et al, 2007), (3) being more risk taking and exploratory when exposed to novelty (Øverli et al, 2006;Frost et al, 2007;MacKenzie et al, 2009) and (4) being more aggressive (dominant) during aggressive encounters (Øverli et al, 2004). In addition, active copers exhibit typical neuroendocrine responses such as (1) lower hypothalamus-pituitary-interrenal (HPI) activity (Silva et al, 2010), (2) lower HPI reactivity (Øverli et al, 2005), (3) higher sympathethic reactivity and lower parasympathetic reactivity (measured as opercular beat rate, e.g.…”

“…Coping styles (or personalities, temperament, behaviour syndromes, bold/shy continuum) are one of such processes and are defined as a coherent set of behavioural and physiological stress responses which is consistent over time and which is characteristic to a certain group of individuals (Koolhaas et al, 1999). Over the past years, several studies have shown that individual variation in a range of behaviour and physiological traits in fish exposed to stress reflect divergent coping styles (Øverli et al, 2005, 2007Frost et al, 2007;Kristiansen and Ferno, 2007;Silva et al, 2010). These studies have gained increasing attention as coping styles have been shown to be key players in fish welfare (Huntingford and Adams, 2005;Huntingford et al, 1999), health and diseases susceptibility (Fevolden et al, 1992;MacKenzie et al, 2009), performance traits (Martins, 2005) and more recently for the interpretation of molecular data (MacKenzie et al, 2009).…”

Evolutionary emergence of responsive and unresponsive personalities

“…In birds, fish, and rodents, for example, some individuals are consistently more aggressive than others, and aggressive individuals differ from nonaggressive individuals in many other respects like foraging behavior or the exploration of novel environments (5). From an adaptive point of view, both the coexistence of behavioral types and the consistency of individuals are poorly understood (10, 11).Many researchers believe that a fundamental factor structuring personality differences is the degree to which individual behavior is guided by environmental stimuli (6)(7)(8)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). Whereas some individuals pay attention to environmental stimuli and quickly adapt their behavior to the prevailing conditions, others show more rigid, routine-like behavior.…”