For example, those who spend money on others are happier (Laura B. Aknin et al., 2013), or in an older study, families of recently deceased loved ones have reported a psychological benefit from their decision to donate organs (Batten & Prottas, 1987). Furthermore, we compare retirees over the age of 65 who volunteer with those who do not (Hunter & Lin, 1980-1981). These studies lack the ability to establish the causal relationship between kindness and happiness. It is possible that a third variable makes individuals happy and helpful, such as health, income, personality, or current mental state. It is crucial to establish a clear causal connection, as kindness interventions may not work from this practical perspective