ORIGINAL PAPER Single vs. Group Mindfulness Meditation: Effects on Personality, Religiousness/Spirituality, and Mindfulness Skills Alessio Matiz 1 & Franco Fabbro 1,2 & Cristiano Crescentini 3 # Springer Science+Business Media, LLC, part of Springer Nature 2017 Abstract Multiple lines of evidence show that mindfulness meditation (MM) improves practitioners’ mental health. To date, most studies have tested the effects of mindfulness-based interventions (MBI), which typically combine the practice of mindfulness with in- class psychoeducation and discussions between teacher and practitioners. However, much less is known about the effects of MM practiced in individual settings. The present research investigated the impact of MM in individual (i.e., single) and group settings by testing mindfulness skills, personality profiles, religious/spiritual self-representation, and adherence to the training program, in relation to two groups of healthy adult practitioners. Findings showed that both groups of participants improved in all outcome measures (mindfulness skills, character maturity, and religiousness/spirituality) with no between-group differences, except for a more pronounced effect on the character maturity of those in an individual MM setting, during the 8-week individual and group MM trainings. Moreover, participants to individual and group MM settings meditated at home for a comparable amount of time and dropped out from their training at similar rates. The results suggest that MBI may have potential benefits both when performed in group settings and in individual settings, emphasizing the importance of mindfulness practice for personal growth and healing. Keywords Single mindfulness meditation . Group mindfulness meditation . Personality . Temperament and Character Inventory . Religiousness/spirituality Introduction Some decades ago, in a fruitful encounter between Western scientific culture and contemplative Buddhist tradition, medi- tation started to be taught in secular contexts such as univer- sities and hospitals by those who foresaw its potential to pro- mote individual and collective well-being. In particular, some interventions emerged inside the medical community, thanks to their standardized structure, which allowed very similar interventions to be applied all around the world and results to be compared. This pushed research based on this technique into a productive cycle, namely a type of meditation known as mindfulness meditation (Baer 2003; Kabat-Zinn 2003; Williams and Kabat-Zinn 2013). Mindfulness-based interventions (MBI), as for example, the mindfulness-based stress reduction program (MBSR; Kabat-Zinn 2003; Santorelli and Kabat-Zinn 2001) or mindfulness-based cognitive therapy (MBCT; Segal et al. 2002; Williams and Kuyken 2012), generally involve groups of participants who demonstrate interest in training, which has a fixed duration of typically 8 weeks. In this period of time, there is a group meeting once a week, during which the prac- tice of mindfulness is combined with frontal teachings about meditation and dialogues between the teacher and their group. The same meditative practice has to be performed autono- mously by participants for about 30–60 min per day. In addi- tion, an all-day retreat can be part of the program. Based on this framework, the number of interventions and related publications focused on psychological well-being and medical symptoms such as stress, anxiety, and depression are growing (Chiesa and Serretti 2011; Keng et al. 2011). Despite these numerous positive aspects, to the best of our knowledge, * Cristiano Crescentini cristiano.crescentini@uniud.it 1 Perceptual Robotics (PERCRO) Laboratory, Scuola Superiore Sant’Anna, Pisa, Italy 2 Department of Medicine, University of Udine, Udine, Italy 3 Department of Languages and Literatures, Communication, Education and Society, University of Udine, Via Margreth 3, 33100 Udine, Italy Mindfulness https://doi.org/10.1007/s12671-017-0865-0