“…In addition, some activities might be more easy to integrate in daily life and thereby be more effective (e.g., self-focused kindness), while other behaviors might be more effective by putting in greater effort (e.g., other-focused kindness; Schiffer and Roberts, 2018 ). Furthermore, where positive emotions might be an important underlying mechanism of positive psychological interventions in general and of acts of kindness in particular (Nelson et al, 2016 ; Hendriks et al, 2020 ), the type of emotions that influence well-being might differ per kindness type. For example, self-focused kindness might elicit low-arousal positive emotions such as relaxation and satisfaction, while other-focused kindness might elicit high-arousal positive emotions such as joy, happiness, and surprise.…”