In their research, they showed that both pure monetary rewards and charitable donations activated the mesolimbic reward pathway, a primitive part of the brain that usually responds to food and sex.
ɪn ðɛɹ ɹᵻsˈɜːtʃ, ðeɪ ʃˈoʊd ðæt bˈoʊθ pjˈʊɹ mˈɑːnɪtˌɛɹi ɹᵻwˈɔːɹdz ænd tʃˈæɹɪɾəbəl doʊnˈeɪʃənz ˈæktᵻvˌeɪɾᵻd ðə mˌɛsəlˈɪmbɪk ɹᵻwˈɔːɹd pˈæθweɪ, ɐ pɹˈɪmᵻtˌɪv pˈɑːɹt ʌvðə bɹˈeɪn ðæt jˈuːʒuːəli ɹᵻspˈɑːndz tə fˈuːd ænd sˈɛks.