The hidden structure of overimitation

Abstract

Young children are surprisingly judicious imitators, but there are also times when their reproduction of others' actions appears strikingly illogical. For example, children who observe an adult inefficiently operating a novel object frequently engage in what we term overimitation, persistently reproducing the adult's unnecessary actions. Although children readily overimitate irrelevant actions that even chimpanzees ignore, this curious effect has previously attracted little interest; it has been assumed that children overimitate not for theoretically significant reasons, but rather as a purely social exercise. In this paper, however, we challenge this view, presenting evidence that overimitation reflects a more fundamental cognitive process. We show that children who observe an adult intentionally manipulating a novel object have a strong tendency to encode all of the adult's actions as causally meaningful, implicitly revising their causal understanding of the object accordingly. This automatic causal encoding process allows children to rapidly calibrate their causal beliefs about even the most opaque physical systems, but it also carries a cost. When some of the adult's purposeful actions are unnecessary-even transparently so-children are highly prone to misencoding them as causally significant. The resulting distortions in children's causal beliefs are the true cause of overimitation, a fact that makes the effect remarkably resistant to extinction. Despite countervailing task demands, time pressure, and even direct warnings, children are frequently unable to avoid reproducing the adult's irrelevant actions because they have already incorporated them into their representation of the target object's causal structure.causal learning ͉ cognitive development ͉ imitation

Limitations to the cultural ratchet effect in young children

“…It is possible that young children do not show the additive type of ratchet effect at all. Indeed, there is a growing literature on young children's tendency to "overimitate" or copy others "too" faithfully (e.g., Flynn, 2008;Lyons, Young, & Keil, 2007;Nielsen & Tomaselli, 2010), and this tendency might well hinder them from coming up with innovations. Indeed, in our rice carrying task, all first-generation children copied the adult's use of the most inefficient tool, the small piece of cardboard, when it was demonstrated pedagogically.…”

The ontogeny of cultural learning

“…Indeed, this tendency is so strong that some researchers have even coined the term 'ritual stance' to capture the fact that when children do not see a clear goal to an actor's action, they imitate even more precisely than if they do see a goal -presumably because the lack of a goal signals a noninstrumental function for the action, which therefore (given that it is being demonstrated) may be of cultural importance (e.g., [5,6]). Also tellingly, human children, but not great apes, copy even irrelevant parts of an action sequence in acts of so-called 'overimitation' ( [7]; see also [8]). And most tellingly of all, human children, but not great apes, conform to others even in situations when they have to override a previously successful strategy to do so, so-called 'strong conformity' [9 ,10 ].…”

The role of parietal cortex in overimitation: a study with fNIRS

“…The child is then instructed to remove the toy from the box as fast as possible. Despite the explicit time constraints, children still imitated both the rational and irrational actions (e.g., the demonstrator stroking the box with a feather), even though the irrational actions were clearly unrelated to the goal (Horner & Whiten, 2005;Lyons et al, 2007).…”

“…Social cues, such as demonstrator status, have been shown to modulate overimitation. For example, it has been shown that children will only reproduce irrational actions when being observed by the demonstrator (Lyons et al, 2007;Nielsen & Blank, 2011). This suggests that overimitation is an important social behavior, and motivates us to explore its neural mechanisms.…”

“…Recently, there has been increased interest in understanding the mechanisms and motivations that determine imitative fidelity (Over & Carpenter, 2012). There are many circumstances in which children and adults imitate other people's actions with very high fidelity, even when this compromises the efficiency of their own actions (Horner & Whiten, 2005;Lyons, Young, & Keil, 2007), a phenomenon termed "overimitation." This paper examines the neural mechanisms supporting imitation and overimitation in the adult parietal cortex, using a novel functional near-infrared spectroscopy (fNIRS) method.…”