Social modules and strict matrilines in social unit A across time. Strict matrilines were defined based on mother–offspring relationships (figure 3). Social modules were based on association as clusters in a daily sampling period, using half-weight indices. Module composition is indicated by block shade, stippled shading indicates uncertainty in module assignment (|eigenvector| less than 0.1), and missing blocks indicate the individual was not seen (and presumably was not alive) in that year. Good divisions within a network are generally indicated by modularity values of roughly 0.3 or greater [68]. Per cent agreement with matrilines (% agreement) does not include uncertain module assignments.