This paper seeks to make a theoretical and empirical case for the importance of differentiated identities for group function. Research on groups has found that groups sometimes perform better and other times perform worse than the sum of their individual members. Differentiation of selves is a crucial moderator. We propose a heuristic framework that divides formation of work or task groups into two steps. One step emphasizes shared common identity and promotes emotional bonds. In the other step, which we emphasize, group members take increasingly differentiated roles that improve performance through specialization, moral responsibility, and efficiency. Pathologies of groups (e.g., social loafing, depletion of shared resources/commons dilemmas, failure to pool information, groupthink) are linked to submerging the individual self in the group. These pathologies are decreased when selves are differentiated, such as by individual rewards, individual competition, accountability, responsibility, and public identification. Differentiating individual selves contributes to many of the best outcomes of groups, such as with social facilitation, wisdom-of-crowds effects, and division of labor. Anonymous confidentiality may hamper differentiation by allowing people to blend into the group (so that selfish or lazy efforts are not punished), but it may also facilitate differentiation by enabling people to think and judge without pressure to conform. Acquiring a unique role within the group can promote belongingness by making oneself irreplaceable.

Social learning from peers can trigger herd-wide intoxication with white locoweed (Oxytropis sericea), an alkaloid-synthesizing herbaceous legume that grows on rangelands of western North America. We conducted an experiment to test the hypothesis that restriction of the area allocated to animals to feed in would inhibit social facilitation of locoweed ingestion in yearling heifers. Eight heifers that avoided white locoweed (LA) and eight heifers that readily consumed it (LE) were selected from a pool of 40 cross-bred heifers and were randomly assigned to the social facilitation or social interference treatment groups. We conducted 200 10-min feeding trials in three 5-day phases (pre-treatment, treatment, post-treatment) during which animals were presented with a set of bowls arrayed in a test arena, some of which contained ground wheat straw and others contained air-dried ground white locoweed. During the pre-treatment (days 1 to 5) and the post-treatment phases (days 11 to 15) non-social trials were conducted in which the feeding behavior of individual animals was investigated in an 80 m2 arena containing 12 feeding bowls. During the treatment phase (days 6 to 10) social learning trials were conducted in which LA + LE pairs from the social interference group were exposed to 12 bowls of food distributed in an 80 m2 arena intended to induce social interference, and LA + LE pairs from the social facilitation group were exposed to 36 bowls of food distributed in a 240 m2 arena intended to permit social facilitation. During pre-treatment phase, LA heifers consumed detectably less locoweed and wheat straw and exhibited lower preference for locoweed than LE (P ⩽ 0.05) although wheat straw preference of LA and LE was similar. During social learning trials (treatment phase), LA in the social interference group visited similar number of locoweed bowls (mean ± s.e.m.: 0.2 ± 0.12) as they had during non-social learning (0.2 ± 0.20). Conversely, LA heifers in the social facilitation group visited detectably more locoweed bowls during social learning trials (1.6 ± 0.46) compared with the pre-treatment phase (0.2 ± 0.16). Correlation between daily number of locoweed bowls visited by LA and LE during social learning trials was detected in the social facilitation (r = 0.70; P < 0.01), but not in the social interference group (r = 0.15; P = 0.52). During testing trials (post-treatment phase), locoweed and wheat straw intake and preference of LA and LE in both treatment groups was similar. Manipulation of the feeding environment delayed, but did not inhibit social learning of toxic weed ingestion in this study.

Social learning can be of critical importance to cattle grazing rangeland environments with high variability of food resources across space and time. Experienced individuals can greatly facilitate foraging decisions (what to eat and where to eat) of naïve peers in such settings. We conducted an experiment with cattle to investigate strength and persistence of socially induced food and feeding site avoidance behaviours. Sixteen naïve yearling steers were paired with 16 social models that had either not been trained (control) or been trained with an emetic (LiCl), electrical shock or both to avoid: (a) an unsafe high-quality food (LiCl); (b) an unsafe high-quality feeding site (shock); or (c) both the unsafe high-quality food and the unsafe high-quality feeding site (LiCl + shock). Ten-minute trials were conducted in an experimental arena containing three artificial feeding sites each consisting of groups of bowls with either high- (HQ) or moderate-quality (MQ) foods (HQ = barley and oat grain; MQ = Bermuda grass hay). Unsafe high-quality (UHQ, surrounded by traffic cones) and safe moderate-quality (SMQ) feeding sites consisted of nine rubber bowls containing either HQ or MQ foods. The safe high-quality (SHQ) feeding site consisted of two groups of eight bowls containing HQ food, which surrounded the UHQ and SMQ feeding sites. Social models did not induce diet and feeding site avoidance behaviours in naïve steers; they exerted small and transient changes in the feeding behaviour of their naïve counterparts. Consequences to the individual outweighed social influences; when naïve animals experienced the same punishment contingencies as their social models, their behavioural patterns closely resembled those of their social model. Conditioned food and location aversions via LiCl were apparently influenced by prior exposure to target foods and the experimental arena. Conversely, conditioned feeding site avoidance via shock was apparently not influenced by prior exposure to target foods or the experimental arena.

Conditioned food aversion is a powerful experimental tool to modify animal diets. We have also investigated it as a potential management tool to prevent livestock from grazing poisonous plants such as tall larkspur (Delphinium barbeyi), white locoweed (Oxytropis sericea) and ponderosa pine (Pinus ponderosa) on western US rangelands. The following principles pertain to increasing the strength and longevity of aversions: mature animals retain aversions better than young animals; novelty of the plant is important, although aversions can be created to familiar plants; LiCl is the most effective emetic, and the optimum dose for cattle is 200 mg/kg body weight; averted animals should be grazed separately from non-averted animals to avoid the influence of social facilitation which can rapidly extinguish aversions. Social facilitation is the most important factor preventing widespread application of aversive conditioning. When averted animals see other animals eat the target food they will sample it, and if there is no adverse reaction they will continue eating and extinguish the aversion. However, if averted animals can be grazed separately, aversions will persist. Aversive conditioning may provide an effective management tool to prevent animals from eating palatable poisonous plants that cause major economic loss.