Participants received a ~5 minute audio recording of visualization Instructions everday for one week. Recordings were delivered via email. Meditators in both conditions were instructed to find a comfortable position, either sitting or lying down, and were then guided through some initial deep breathing. Meditators in the visualization condition were asked to visualize specific details of their target close friend's appearance. After approximately 5 minutes, meditators were guided back to relaxation.

The willingness to sacrifice scale is a two-item measure adapted from the Marburg Attitude Inventory for Styles of Loving (Bierhoff et al., 1993). Participants are asked to respond to the following questions on a scale from 1-10 (1 = Not at all; 10 = Entirely): "To what extent would you be willing to sacrifice your own desires for your close friend's desires?"; and "To what extent would you leave everything else aside for your close friend?". At baseline and follow-up, participants responded to these questions based on the previous week. For each administration, a mean score was calculated for use in data analyses.

The Inclusion of the Other in the Self Scale (IOS; Aron et al., 1992) is a one item measure composed of seven images of two increasingly overlapping circles labeled "self" and "other". Other-inclusive self-concept was measured with a modified IOS by asking participants to think about their relationship with their chosen close friend over the past week and to indicate the diagram that best matched their perceived connection. The IOS has convergent validity (Aron et al., 1992; Gächter et al., 2015) and discriminant validity (Aron et al., 1992) in relation to other established interpersonal closeness measures.

A modified version of the Rochester Interaction Record (M-RIR; based on Wheeler & Reis, 1991) was used to measure interaction quality. The M-RIR asks participants to rate, from 1-7, the degree to which their interactions with their close other: 1) were intimate (1 = superficial; 7 = meaningful); 2) included self/other disclosure (1 = very little; 7 = a great deal); 3) were satisfying (1 = very unsatisfying; 7 = very satisfying); 4) were loving (1 = not at all loving; 7 = very loving); 5) were supportive (1 = not at all supportive; 7 = very supportive); and 6) were stressful (1 = not at all stressful; 7 = very stressful; reverse coded). At baseline and follow-up, participants completed the M-RIR for the past week. A mean score was calculated for use in data analyses, with higher scores indicating greater interaction quality.

The anxious arousal subscale of the Mood and Anxiety Symptom Questionnaire (MASQ; Clark & Watson, 1991) was used to measure anxious arousal.

Participants rated items of the MASQ (Clark & Watson, 1991) on a scale from 1-5 (1 = Not at All; 5 = Extremely) based on how they felt over the past week. The anxious arousal subscale includes 17 items (e.g., "Was trembling or shaking"). For each subscale, a mean score was calculated, with higher scores indicating more anxious arousal.

The Positive Affect Negative Affect Schedule (PANAS; Watson et al., 1988) was used to measure negative affect. The PANAS consists of 20 emotion words divided into two subscales (10 positive words and 10 negative words). Participants rate each emotion word on a scale from 1-5 (1 = Very Slightly or Not at All; 5 = Extremely) corresponding to how they have been feeling over the past week. The negative affect subscale contains emotion words such as "Hostile", "Irritable", and "Ashamed'". A mean score was calculated for use in data analyses, with higher scores indicating greater negative affect.

Emotional closeness was measured using a modified 10-item version of the Emotional Closeness Questionnaire (ECQ; Flores & Berenbaum, 2012, 2014). The ECQ presents participants with 10 statements that reflect aspects of emotional closeness (e.g., "my friend gave me emotional support", "I shared my personal thoughts or feelings with my friend"). Respondents rate the degree each of these statements happened over the past week on a scale of 1 (not at all) to 5 (extremely). Scores from each question are averaged to create an overall score with higher scores indicating higher levels of emotional closeness (Flores & Berenbaum, 2012, 2014). This questionnaire was modified to ask respondents to specifically consider the close other they chose at the beginning of the study.

Desired emotional closeness was measured using a modified 10-item version of the Emotional Closeness Questionnaire (ECQ; Flores & Berenbaum, 2012, 2014). The D-ECQ presents participants with 5 statements that reflect aspects of emotional closeness (e.g., "my friend gives me emotional support", "I share my personal thoughts or feelings with my friend"). Respondents rate the degree to which they would have liked each of these statements to have happened over the past week on a scale of 1 (not at all) to 5 (extremely). Scores from each question are averaged to create an overall score with higher scores indicating a higher desire for emotional closeness (Flores & Berenbaum, 2012, 2014). This questionnaire was modified to ask respondents to specifically consider the close other they chose at the beginning of the study.

The Penn State Worry Questionnaire (PSWQ; Meyer et al., 1990) was used to measure worry. The PSWQ asks participants to rate the degree to which 16 statements related to worry are typical or characteristic of them (e.g., "My worries overwhelm me", "Once I start worrying, I can't stop"). Respondents rate each item on a scale from 1 (not at all typical) to 5 (very typical; Meyer et al., 1990). A mean score was generated for each participant with higher scores indicating higher levels of worry.

Prior to the meditation, participants were asked to rate on a scale from 1-10: "how much negative emotion are you feeling right now?" (higher numbers indicating more negative emotion). After completing the meditation, this question was repeated.

Prior to the meditation, participants were asked to rate on a scale from 1-10 "how much positive emotion are you feeling right now?" (higher numbers indicating more positive emotion). After completing the meditation, this question was repeated.

Prior to the meditation, participants were asked to rate on a scale from 1-10 "how socially connected to your friend are you feeling right now?" (higher numbers indicating more feelings of social connection). After completing the meditation, this question was repeated.