characteristic rather than due to overt reputational concerns and simply pointing out that there are reputational benefits of an action may actually reduce them. This may possibly be used as derogatory tactic against altruists, especially by those who are non-cooperators. A counterargument is that doing good due to reputational concerns is better than doing no good at all. Group selection. It has controversially been argued by some evolutionary scientists such as David Sloan Wilson that natural selection can act at the level of non-kin groups to produce adaptations that benefit a non-kin group even if these adaptations are detrimental at the individual level. Thus, while altruistic persons may under some circumstances be outcompeted by less altruistic persons at the individual level, according to group selection theory the opposite may occur at the group level where groups consisting of the more altruistic persons may outcompete groups consisting of the less altruistic persons. Such altruism may only extend to ingroup members while directing prejudice and antagonism against outgroup members (see also in-group favoritism). Group selection theory has been criticized by many other evolutionary scientists. Such explanations do not imply that humans are always consciously calculating how to increase their inclusive fitness when they are doing altruistic acts. Instead, evolution has shaped psychological mechanisms, such as emotions, that promote altruistic behaviors. Not every single instance of altruistic behavior necessarily leads to an increase of inclusive fitness since, if that was the case in the ancestral environment, then altruistic behaviors would have been selected. This also does not imply that on average 50% or more of altruistic acts were beneficial for the altruist in the ancestral environment -- if the benefits from helping the right person were very high it would be beneficial to err on the side of caution and usually be altruistic, even if in most cases there were no benefits. The benefits for the altruist may be increased and the costs reduced by being more altruistic towards certain groups. Research has found that people are more altruistic to kin than to no-kin, to friends than to strangers, to those attractive than to those unattractive, to non-competitors than to competitors, and to members ingroups than to members of outgroup. The study of altruism was the initial impetus behind George R. Price's development of the Price equation, which is a mathematical equation used to study genetic evolution. An interesting example of altruism is