Cultural variation in the main finding.

<p>Panel (a): the ratio between same-gender and mixed gender pictures of different group size (corrected by the probability of appearance, see text). Panel (b): number of close friends (same gender, with groups size 2 to 4). Panel (c): the ratio between same-gender Profile Pictures as a function of group size (1F/1M normalised to 0). Panel (d): cultural variation in the proportion of single person pictures within all Profile Pictures in a given global region. (Region codes of Panels a-c: green: Central and South Asia, blue: Europe, dashed blue: Latin America, dashed green: Middle East and North Africa, dotted blue: North America, dotted green: South-East Asia, red: Sub-Saharan Africa, black: Australia, dashed black: East Asia.)</p

The ratio of same-gender women-only to men-only frequencies (nF/nM as function of n).

<p>Gray lines denote a one-standard-deviation band from bootstrapping. Above n>4, men-only groups dominate, while women-only groups become extremely rare. The linear OLS coefficient of nF/nM as a function of n is negative, with R² = 0.86, and p<0.01</p

Homophobia is not related to the frequency of 2F Profile Pictures, bootstrapping distributions.

<p>Blue line: highly homophobic countries; red line: countries with low homophobia (see text for definitions). Dashed black line: the (2F/1F)/(2M/1M)-1 mean of the entire database. (100,000 bootstrapping repeats.)</p

Coding categories.

<p>Coding categories.</p

Bootstrap histograms.

<p>Panel (a): the ratio of same gender Profile Pictures compared to mixed gender profile pictures (probability corrected); green, red, and blue lines correspond to n = 2, 3, and 4. Panel (b): the number of people on a Profile Picture men (red) or women (blue) appear on; straight lines: same gender with <i>n</i> between 2 and 4, dashed lines: mixed gender with <i>n</i> between 2 and 4, dotted lines: mixed gender with <i>n</i> between 2 and 20. Panel (c): the ratio of the frequency of same-gender pictures between the genders; green: pictures with 1 person, red: 2 persons, brown: 3 persons, and blue: 4 persons. (100,000 bootstrapping repeats.)</p

The ratio of men in Profile Pictures (with same age adults only) as a function the number of persons in the picture.

<p>The value corresponding to each <i>n</i> adds up to 1. The size of the disks denotes the share in the ratio at that particular bin. Crossing points on the grid are the only possible points given the discrete nature of the data.</p