Table 3.

Summary of Included Studies

Reference (Bias Risk)	Sample	Meditation Intervention	Control Group	Intervention dose	Intervention Adherence	Outcome Variables	Results
Ashar et al., 2016 (medium)	N = 58 non-clinical adults; non-meditators; 63% F, 81% W, Mage = 28.59	CM; individual, audio recording	Oxytocin placebo Strangers’ photos and brief stories	20 minutes daily × 4 weeks; no home practice	Sessions completed: 74%	(S) Compassion composite score	+
						(O) Charitable donations	−
Asuero et al., 2014 (medium)	N = 68 PCPs in Spain; 92% F, Mage = 47.00	MM; group, in person	Wait-list	2.5 hours once/week × 8 weeks; one 8-hour retreat; “regular” home practice	Retention: 100% Session attendance: 92% Home practice adherence: 85%	(S) Jefferson empathy questionnaire	+
Condon et al., 2013 (medium)	N = 39 non-clinical adults; non-mediators; 74% F, Mage = 25.23	MM; group, in person CM; group, in person	Wait-list	2 hours once/week × 8 weeks; 20 minutes daily home practice	Session attendance: M = 6.60 sessions Home practice: M = 3.74 practices/week	(O) Giving up a seat for an injured person	+ no meditation group differences
Flook et al., 2015 (medium)	N = 68 children; 50% F, 59% W, Mage = 4.67	Kindness Curriculum group, in person	Wait-list	20-30 minutes 2×/week × 12 weeks	Not reported	(O) Teacher-rated social competence	+
						(O) Sharing task	+
He et al., 2015 (medium)	N = 55 Chinese college students; non-meditators; 84% F, Mage = 18.5	LKM; group, video	No intervention	30 minutes 3×/week × 4 weeks	Not reported	(S) Inclusion of Other in Self Scale	+
Hutcherson et al., 2008 (medium)	N = 93 non-clinical adults; non-meditators; 57% F, 46% W, Mage = 23.6	LKM; individual, audio recording	Imagining others’ physical appearance	one 7-minute practice	N/A	(S) explicit attitudes toward others	+
						(O) Implicit attitudes task	+
Jazaieri et al., 2013 (low)	N = 100 non-clinical adults; 72% F, 71% W, Mage = 43.33	CM; group, in person	Wait-list	2 hours once/week × 8 weeks; 15 minutes daily home practice	Session attendance: 98% ≥7 sessions Retention: 85% Home practice: M = 101.11 minutes/week	(S) Fear of compassion scale	+
Kang et al., 2014 (low)	N = 101 non-clinical adults; non-meditators; 64% F, 61% W, Mage = 25.20	LKM; group, in person	Discussion about loving kindness Wait-list	1 hour once/week × 6 weeks; 20 minutes home practice × 5days/week	Session attendance: M = 4.86 sessions Home practice: M = 553.84 minutes	(S) explicit bias	−
						(O) Implicit attitudes task	+
Kang et al., 2015 (low)	N = 54 non-clinical adults; non-meditators; 67% F, 59% W, Mage = 24.94	LKM; group, in person	Discussion about loving kindness Wait-list	1 hour once/week × 6 weeks; 20 minutes home practice 5 days/week	Session attendance: M = 4.30 sessions	(S) Self-Other Four Immeasurables scale	+
Keefe, 1979 (low)	N = 56 social work students	Meditation, not specified	Empathy education No intervention	30 minutes daily × 3 weeks	Not reported	(S) Kagan affective sensitivity scale	−
Kemeny et al., 2012 (low)	N = 76 female school teachers; non-meditators; Mage = 41.05	MM, LKM, yoga; group, in person	Wait-list	42 hours over 8 weeks; 25 minutes daily home practice	Session attendance: M = 6.67 sessions	(O) Emotional recognition task; implicit compassion task; marital interaction task; 5 month f/u	+ follow-up: +
Kok et al., 2013 (high)	N = 65 university faculty; non-meditators; 66% F, 83% W, Mage = 37.5	LKM; group, in person	Wait-list	1 hour once/week × 6 weeks; daily home practice	Not reported	(S) daily social connectedness; 1-week post intervention	+
Logie et al., 2015 (medium)	N = 105 undergraduate students; mostly non-meditators; 67% F, 63% W, Mage = 18.63	LKM; individual, audio recording MM, individual, audio recording	Read about mindfulness	one 15-minute practice	NA	(S) Self-Other Four Immeasurables scale	+ no meditation group differences
						(O) Self/other referential processing task	+ no meditation group differences
Mascaro et al., 2013 (low)	N = 29 non-clinical adults; 45% F, Mage = 31.0	CM	Health education	2 hours once/week × 8 weeks; 20 minutes daily home practice	Session attendance: M attendance = 7.38 sessions Home practice: M = 315.9 minutes	(O) Empathic accuracy task	+
Oman et al., 2010 (medium)	N = 58 healthcare providers; 40% meditators; 86% F	Passage meditation; group, in person	Wait-list	2 hours once/week × 8 weeks	Not reported	(S) IRI; MMRS; compassionate love scale; altruism scale; post, and 8- and 19-week f/u	+ follow-up: +
Pearl et al., 1994 (medium)	N = 50 non-clinical adults; non-meditators; Mage = 23.9	Meditation, not specified	No intervention	Approximately eight weeks	Not reported	(S) Affective sensitivity scale	−
Poehlmann-Tynan et al., 2016 (medium)	N = 29 children; 49% girls, Mage = 3.92	Kindness Curriculum; group, in person	Reading group	20–30 minutes 2×/week × 12 weeks	Session attendance: M = 21 sessions	(O) Response to someone getting ‘hurt’; compassionate stories; 3-month f/u	− follow-up: −
Rosenberg et al., 2015 (low)	N = 60 experienced meditators; 54% F, Mage = 48	MM and CM retreat; group and individual	Wait-list	3-month retreat	Retention: 100% Total practice: M = 41 hours	(S) Emotions composite	−
						(O) facial coding during film clips of suffering	+
Schonert-Reichl et al., 2015 (low)	N = 100 children; 46% F, 66% English first language, Mage = 10.24	MM and prosocial; group, in person	Social responsibility education	40–50 minutes once/week × 12 weeks	100% of lessons administered	(S) IRI; Social Goals questionnaire	+
						(O) Peer-reported prosociality	+
Shapiro et al., 1998 (medium)	N = 78 medical students; 64% F, 79% W	MM, LKM; group, in person	Wait-list	2.5 hours once/week × 7 weeks; weekly home practice	Retention: 97%	(S) Empathy rating scale	+
Shapiro et al., 2010 (low)	N = 30 undergraduate students; 87% F, 83% W, Mage = 18.73	MBSR; group, in person	Wait-list	90 minutes once/week × 8 weeks	Retention: 100%	(S) IRI, Heartland forgiveness scale; 2- and 12-month f/u	+ follow-up: +
Taylor et al., 2015 (medium)	N = 59 teachers; 90% F, 67% W, Mage = 47.00	MM and compassion; group, in person	Wait-list	11 sessions over 9 weeks (36 hours total); daily practice	Session attendance: Mode = 9 sessions Home practice: M = 12.8 hours	(S) Santa Clara compassion scale; Tendency to Forgive scale; specific person forgiveness	+
Velasquez et al, 2015 (high)	N = 125 children in Colombia	Yoga; group, in person	Wait-list	2 hours twice/week × 12 weeks	Session attendance: M = 17 sessions	(S) Empathy questionnaire	−
						(O) Peer prosociality	−
Wallmark et al., 2013 (high)	N = 46 non-clinical adults; non-meditators; 86% F, Mage = 33.8	MM and FI; group, in person	Wait-list	75 minutes once/week × 8 weeks; 30 minutes daily home practice	Not reported	(S) IRI	+
Weng et al., 2013 (low)	N= 56 non-clinical adults; non-meditators; 61% F, Mage = 22.5	CM; individual, audio recording	Cognitive reappraisal No intervention	30 minutes daily × 2 weeks	Home practice: M = 11.8 days of practice, M = 351.7 minutes total	(O) Redistribution of money game	+
Weng et al., 2015 (low)	N= 56 non-clinical adults; non-meditators; 61% F, Mage = 22.5	CM; individual, audio recording	Cognitive reappraisal No intervention	30 minute daily × 2 weeks	Home practice: M = 11.8 days of practice, M = 351.7 minutes total	(O) Redistribution of money game	+

Note. Results are in reference to the significance of the group * time interaction, such that positive findings (+) indicate significantly greater improvements in the meditation group compared to the control group, and negative findings (−) indicate no greater benefits of meditation compared to the control group. F = female, W = white. CM = compassion meditation, MM = mindfulness meditation, LKM = loving kindness meditation. S = subjective (self-reported) outcomes, O = objective (observable) outcomes. All outcomes were assessed immediately post-intervention and outcomes that were also measured at longer-term follow-ups are noted. IRI = Interpersonal Reactivity Index (Davis, 1994); MMRS = Multidimensional Measure of Religion and Spirituality (Fetzer, 1999).