The effect of loving-kindness meditation on positive emotions: a meta-analytic review

Abstract

While it has been suggested that loving-kindness meditation (LKM) is an effective practice for promoting positive emotions, the empirical evidence in the literature remains unclear. Here, we provide a systematic review of 24 empirical studies (N = 1759) on LKM with self-reported positive emotions. The effect of LKM on positive emotions was estimated with meta-analysis, and the influence of variations across LKM interventions was further explored with subgroup analysis and meta-regression. The meta-analysis showed that (1) medium effect sizes for LKM interventions on daily positive emotions in both wait-list controlled RCTs and non-RCT studies; and (2) small to large effect sizes for the on-going practice of LKM on immediate positive emotions across different comparisons. Further analysis showed that (1) interventions focused on loving-kindness had medium effect size, but interventions focused on compassion showed small effect sizes; (2) the length of interventions and the time spent on meditation did not influence the effect sizes, but the studies without didactic components in interventions had small effect sizes. A few individual studies reported that the nature of positive emotions and individual differences also influenced the results. In sum, LKM practice and interventions are effective in enhancing positive emotions, but more studies are needed to identify the active components of the interventions, to compare different psychological operations, and to explore the applicability in clinical populations.

Positive Emotion Correlates of Meditation Practice: a Comparison of Mindfulness Meditation and Loving-Kindness Meditation

“…The scientific study of LKM has mushroomed since 2008, which marked the first published scientific studies on LKM (Fredrickson et al, 2008; Hutcherson, Seppala, & Gross, 2008). Two recent meta-analyses conclude that LKM interventions improve health and wellbeing more generally (Galante, Galante, Bekkers, & Gallacher, 2014), and, with medium effect size, positive emotions specifically (Zeng, Chiu, Wang, Oei, & Leung, 2015). LKM has also been shown to reduce depressive symptoms (Fredrickson et al, 2008), increase compassion and altruistic behavior (Jazaieri et al, 2013; Klimecki, Leiberg, Lamm, & Singer, 2013; Leiberg, Klimecki, & Singer, 2011; Weng et al, 2013), and yield functional neural plasticity in brain circuits associated with positive affect and empathy (Klimecki et al, 2013; Weng et al, 2013).…”

“…LKM has also been shown to reduce depressive symptoms (Fredrickson et al, 2008), increase compassion and altruistic behavior (Jazaieri et al, 2013; Klimecki, Leiberg, Lamm, & Singer, 2013; Leiberg, Klimecki, & Singer, 2011; Weng et al, 2013), and yield functional neural plasticity in brain circuits associated with positive affect and empathy (Klimecki et al, 2013; Weng et al, 2013). Despite the surge in scientific publications on LKM, the two meta-analyses cited above conclude that research on LKM remains in “the beginning stages” (Zeng et al, 2015, p. 13) and is “underpowered” and “generally underresourced” (Galente et al, 2014, p. 1111). As such, any meta-analytic conclusions are at best provisional.…”

“…Most reviews of meditation research conclude by noting widespread methodological shortcomings (Galente et al, 2014; Ospina et al, 2008; Zeng et al, 2015). Among these limitations are: (a) small sample sizes, which lead to both lower statistical power and greater baseline imbalances (May, Johnson, & Weyker, 2016); (b) failure to report participants' actual practice time despite the need to elucidate dose-response relations (Edenfield & Saeed, 2012); (c) failure to examine within-person relations, which offer insight into day-to-day processes and better match theoretical questions about change over time (Curran & Bauer, 2011; Kanning, Ebner-Priemer, & Schlicht, 2013); (d) a lack of longitudinal, randomized controlled trials (RCTs) with novice, non-clinical samples, which enable stronger inference about the effects of learning a new meditation practice; and (e) inadequate measurement of positive emotions by relying either on global, retrospective reports of happiness, or on measures (e.g., PANAS; Watson, Clark, & Tellegen, 1988) that omit the low activation positive emotions (e.g., “calm,” “relaxed,” “peaceful”) often sought by meditation practitioners (Koopmann-Holm, Sze, Ochs, & Tsai, 2013).…”

Compassion Meditation for Posttraumatic Stress Disorder in Veterans: A Randomized Proof of Concept Study

“…One of the mechanisms by which CM and LKM may be helpful is through generating positive emotion (Zeng, Chiu, Wang, Oei, & Leung, ); this is important because of its association with increased coping and resilience (Fredrickson, Tugade, Waugh, & Larkin, ). For example, evidence from functional magnetic resonance imaging has demonstrated activation in areas of the brain typically associated with positive affect (i.e., left medial prefrontal cortex and anterior cingulate gyrus) in an expert meditator engaged in CM (Engstrom & Soderfeldt, ), and a brief LKM exercise in a laboratory setting was shown to increase positive mood and decrease negative mood to a greater extent than did imagery in participating individuals (Hutcherson, Seppala, & Gross, ).…”

Meditation as an Intervention for Health: A Framework for Understanding Meditation Research

“…Published research comparing "types of meditation" could benefit from including our framework and then clarifying which element or elements they are comparing. For example, some studies have compared Mindfulness and Lovingkindness practices (two specific, common Buddhist meditations that are also part of Mindfulness Based Stress Reduction) [25][26][27]. Based on our framework, this comparison derives from both object and the experience of meditation.…”