One brain region, the subgenual anterior cingulate cortex/basal forebrain, contributes to learning altruistic behavior, especially in people with  empathy.
wˈʌn bɹˈeɪn ɹˈiːdʒən, ðə sˈʌbdʒənjˌuːəl æntˈiəɹɪɚ sˈɪŋɡjʊlˌeɪt kˈɔːɹɾɛks slˈæʃ bˈeɪsəl fˈɔːɹbɹeɪn, kəntɹˈɪbjuːts tə lˈɜːnɪŋ ˌɔːltɹuːˈɪstɪk bᵻhˈeɪvjɚ, ɪspˈɛʃəli ɪn pˈiːpəl wɪð ˈɛmpəθi.