Personality pace-of-life hypothesis: testing genetic associations among personality and life history

• Published in: Behavioral ecology 2013-07, Vol.24 (4), p.935-941
• Main Authors: Niemelä, Petri T., Dingemanse, Niels J., Alioravainen, Nico, Vainikka, Anssi, Kortet, Raine
• Format: Article
• Language: English
• Subjects: Gryllidae; Gryllus integer
• ISSN: 1045-2249; 1465-7279
• DOI: 10.1093/beheco/art014

Over the last few years, animal personality researchers have called for integrative approaches to study behavioral, immunological, and life-historical traits. This is because life history and personality have become implied as part of integrative "pace-of-life" syndromes. Immune defense is one of the traits that have been suggested to associate with personality traits, such as boldness, mainly because behavioral types may differ in parasite encounter rates. Here, we quantified the narrow-sense heritabilities (h super(2) = V sub(A)/(V sub(A) + V sub(R))) and genetic (r sub(A)) and phenotypic (r sub(P)) correlations between 2 measures of behavior (overall boldness and defreezing, i.e., recovery from disturbance-induced immobility), 1 measure of immune function (encapsulation response), and 2 life-history traits (body mass and maturation time) using the western stutter-trilling cricket, Gryllus integer. All nonbehavioral traits showed strong heritabilities (range: encapsulation response and life-history: h super(2) = 0.42-0.84), whereas behaviors were only marginally heritable (h super(2) = 0.06-0.11). Boldness and encapsulation were positively associated, and defreezing and body mass were negatively associated phenotypically, whereas only defreezing was positively genetically correlated with encapsulation. However, the lack of significant additive genetic variation in defreezing suggests that the genetic correlation may be an artifact and therefore, that there were only environmentally induced phenotypic correlations between behaviors and other measured traits. Life-history traits and encapsulation were positively phenotypically associated and these associations were mostly genetically underpinned. Overall, our results support the hypothesis that life history is structured in an evolutionarily significant "pace-of-life" syndrome, but suggest that behavior does not intrinsically integrate with such life-history variation.