Many people seem to be following a similar strategy by cooperating if and only if others cooperate in return.
mˈɛni pˈiːpəl sˈiːm təbi fˈɑːloʊɪŋ ɐ sˈɪmɪlɚ stɹˈæɾədʒi baɪ koʊˈɑːpɚɹˌeɪɾɪŋ ɪf ænd ˈoʊnli ɪf ˈʌðɚz koʊˈɑːpɚɹˌeɪt ɪn ɹᵻtˈɜːn.