Following home cage alcohol habituation, animals were subjected to operant alcohol SA (Figure 2A). Already in the first SA session, animals learned to discriminate between the active and the inactive hole, preferring the alcohol‐associated one: paired t test, FR1active vs FR1inactive controls, t(14) = 5.95, P < 0.001; SDPS prone, t(9) = 3.45, P = 0.007; and SDPS resilient, t(9) = 2.77, P = 0.022 (Figure 2B, Figure S2). Analysis of active responding during the three FR (1‐3) reinforcement schedules revealed an overall effect of training, representing an increase in responding following each change in schedule. Next, an overall effect of SDPS was observed for all three training ratios, and socially defeated animals, independently of subgroup, displayed increased number of responses in comparison with controls, as observed previously.20 No training × group interaction effect was seen in any of the FRs tested, and no differences between SDPS‐prone and SDPS‐resilient animals were observed (for effects per FR schedule and pairwise group comparisons, see Table S1).
