Family transfers, like parents giving money to adult children or children caring for elderly parents, are not fully explained by traditional economic models. Researchers have identified three main reasons for these transfers: pure altruism, where parents give to children out of love; impure altruism, where parents give to influence their children's behavior; and non-altruistic reciprocity, where transfers are investments for the future. These transfers can affect inequality within and between generations. While pure altruism doesn't fully explain these transfers, they are not solely based on direct exchanges either.