The idea of community as method of treatment is fundamental to therapeutic communities. However, there has been little research seeking a deeper understanding of the mechanisms that underpin its functioning. Drawing on contemporary results in evolutionary game theory, we argue that residents will receive help in the form of affirmations in proportion to their reputations for giving help in the form of affirmations and corrections. We test this hypothesis using localised regression modelling of data on affirmations received and affirmations and corrections given during residence in a 90-bed corrections-based therapeutic community. Consistent with our hypothesis, we find that both affirmations and corrections given predict affirmations received. These relationships are positive over most of the range of data; however, the relationship between affirmations given and received flattens at high numbers of affirmations given, while that between corrections given and affirmations received grows negative at high levels of corrections given. Thus, while these results support the hypothesis that those who give more help also receive more, there seems to be limits to this effect. (PsycINFO Database Record (c) 2017 APA, all rights reserved)