A decade ago, the term emulation had been used by Tomasello (1990) to describe the performance of chimpanzees that seemed to him neither imitative nor a result of simple motivational or attentional influences. However, some researchers have questioned if emulation has been sufficiently well established to be used as a valid alternative in attempts to discover imitation, and whether its definition is precise enough for reliable identification of its operation (Byrne, 1998). As is a common feature of the social learning literature, the term has different meanings in different domains (e.g. Wood, 1989; Whiten and Ham, 1992). Let me first recall what Tomasello and his colleagues (Tomasello et al., 1987; Tomasello, 1990, 1996, 1998) have found and then add some recent evidence, including our findings, for this underestimated learning phenomenon. This endeavour will not only reveal that many findings reported in the literature support the emulation learning account if re-evaluated by recent methodological and theoretical developments (Huang et al., 2002; Want and Harris, 2002; Horowitz, 2003; Whiten et al., 2004; Zentall, 2004), but also that imitation has been dramatically overestimated in terms of occurrence and importance.

In a study by Tomasello et al. (1987) different groups of chimpanzees were presented with three experimental conditions. The first group observed a conspecific demonstrator using a T-bar to rake food items into reach. The second group observed a chimpanzee simply manipulating the tool without a food item being present. The third group did not observe any demonstrator.