Behavioral syndrome

In behavioral ecology, a behavioral syndrome is a correlated suite of behavioral traits, often (but not always) measured across multiple contexts. The suite of traits that are correlated at the population or species level is considered the behavioral syndrome, while the phenotype of the behavioral syndrome an individual shows is their behavioral type. For example, a population may show a behavioral syndrome that includes a positive correlation between foraging behavior and mating behavior. An individual may be more or less aggressive than another individual within this behavioral syndrome, and this aggressive or passive phenotype is that individual's behavioral type. In behavioral ecology, a behavioral syndrome is a correlated suite of behavioral traits, often (but not always) measured across multiple contexts. The suite of traits that are correlated at the population or species level is considered the behavioral syndrome, while the phenotype of the behavioral syndrome an individual shows is their behavioral type. For example, a population may show a behavioral syndrome that includes a positive correlation between foraging behavior and mating behavior. An individual may be more or less aggressive than another individual within this behavioral syndrome, and this aggressive or passive phenotype is that individual's behavioral type. For example, the lizards Eulamprus heatwolei show a behavioral syndrome with two behavioral types. There is a correlated relationship between how territorial an individual is, how likely they are to explore their environment, and what strategy they use to avoid predation. This behavioral syndrome has also been shown to influence the mating system of this species; territorial males are more likely to sire offspring with territorial females, and larger territorial males compete less with other males for mates. However, less territorial, or 'floater', males and females produce consistently larger offspring than territorial parents or hybrids. Behavioral syndrome is a term that originated in the psychology literature. It was originally used to describe human behavioral disorders, including nervous and stereotypical behaviors. These often included pacing, involuntary muscle twitches, and repetitive self-mutilation. The term became less popular in the late 1970s and 80s. Through the 90s, it was infrequently used analogously for 'personality' in some behavioral ecology literature, but it was still primarily used in psychology literature to describe inter-individual differences in behavior to model systems like rodents and primates. While a behavioral syndrome is a concept still used in multiple disciplines, the term was adopted by behavioral ecologists and re-defined in 2004. It has become a popular field of study, both empirically and theoretically. Often, behavior is considered infinitely plastic and can easily be adapted to changing environmental conditions. However, the nature of behavioral syndromes implies that there can be constraints on the behavior of an individual. This can (though it is not required to) lead to the non-optimal behavior that has long been puzzling to behavioral ecologists (e.g., attacking a predator when fleeing is a better option). Given that behavioral syndromes come with perceived costs, it would be expected for evolution to have selected against them. As such, there are four primary reasons for the persistence of behavioral syndromes: (1) pleiotropy, linkage disequilibrium, or other mechanistic restrictions; (2) the benefit of consistency to mitigate against errors; (3) the benefits of specialization; and (4) the benefits of predictability in social interactions. It is important to emphasize that while these may mitigate the costs associated with limited behavioral plasticity, behavioral syndromes themselves do not necessarily imply they create sub-optimal behavior. See Misconceptions. The field of behavioral syndromes often focuses on describing behavioral types. However, the phenotypic correlations that form behavioral types do not necessarily signify that they have a genetic basis. While behavioral syndromes are theoretically not required to be the byproduct of genetics, understanding if a specific syndrome is genetically based may be important, as this determines heritability. Without a genetic basis, behavioral syndromes must be the result of environmental conditions. Recent studies have shown that some behavioral syndromes have a genetic basis. Additionally, some of these genetic correlations that shape behavioral syndromes can evolve. For example, researchers were able to separate the genetically determined traits of body size, nest size, and foraging behavior in laboratory mice.