London: Some individuals appear to be genetically programmed to help others whilst living side-by-side with others who tend to exploit their generosity, say researchers who produced an innovative model of social evolution to understand the concept of genetic polymorphism. Behaviours of humans are very flexible and they tend to base their perception on what they see after processing information about the world. "However, some species rely on inherited instructions on what to do - individuals behave differently according to which specific genetic variants they are born with," said one of the researchers Sasha Dall, Senior Lecturer at University of Exeter in Britain. The findings showed that people are likely to be influenced by conditioning or the surrounding environment rather than what they sense or experience. The behaviour of individuals can often evolve to be determined by a set of inherited genetic tendencies that accurately predict social relationships, including their likely relatedness to other members of their community, and their surroundings rather than in direct response to what they sense or experience. The study, published in the journal PLOS Computational Biology, aims to explore why some individuals evolve to be genetically programmed to be nice, while others stay nasty. The theory of kin selection explains the evolution of helping when relatives interact. It can be used when individuals in a social group have different sexes, ages or phenotypic qualities, but the theory has not been worked out for situations where there is genetic polymorphism in helping, the researchers said. "Social evolution theory hasn't previously addressed genetic polymorphism. We have developed a model that allows us to explore this within a general framework alongside other behavioural influences,” added lead author Olof Leimar, Professor at Stockholm University. Thus, for the study, the team used colony-living microbes as inspiration to explore why some individuals are by nature generous and others less so. Using a mathematical model, they examined the social behaviour in a range of different species to understand the evolution of sociality. “What we have been able to show is how you can get a situation where you end up with distinct levels of genetically determined niceness coexisting within populations," Dall noted.