Overimitation A uniquely human trait

Overimitation – Not to be confused with Regular Imitation Overimitation: copying causally irrelevant actions in goal-directed action sequence. Example: When showing a child how to open a box, wave a stick over the top three times.

Is overimitation a universal trait? Comparing Cultures Bushman children vs. Australian children: Nielsen & Tomaselli Three sets of objects: three boxes opened by latch, knob, or sliding mechanism accompanied by stick or rubber mallet Two conditions – demonstration and no-demonstration Demonstration – experimenter performed irrelevant and unnecessary actions No-Demonstration – child given 60 seconds to explore objects and attempt to open box Findings: Regardless of cultural background, children in demonstration group performed all actions, whereas children in no-demonstration group performed none of the irrelevant or unnecessary actions.

Is overimitation a universal trait? Variations: No-demonstration group – After the 60 seconds were up, the experimenter demonstrated the actions as in the demonstration condition. Children imitated all actions, even if they had figured out on their own how to open the box in a more efficient manner. Experimenter vs. Community member – Some children had a member of their community demonstrate the actions. Regardless of who modeled the behavior, children imitated the actions. Young vs. Older children – When comparing data between age groups, older children (6-13) imitated more frequently than younger children (2-5).

Why do we do it? Automatic Causal Encoding (ACE) Lyons, et al. Process by which children automatically code an adult’s purposeful action as causal Useful when learning a new task Leads to incorrectly coding unnecessary and irrelevant actions as causal, which leads to overimitation Experiment: Taught children to identify “silly” actions. When presented with novel object, they reverted back to overimitation.

Why do we do it? ACE Variations Findings: Time sensitivity Competition – Felix the Orangutan Findings: Even though children taught to identify irrelevant and unnecessary actions, when presented with a novel object they overimitated. Introduction to time sensitivity and competition did not effect number of irrelevant actions produced. Simply put, children overimitate because they believe the adults will only perform necessary actions. https://www.youtube.com/watch?v=yMSGCOClJcs&feature=player_embedded https://www.youtube.com/watch?feature=player_embedded&v=twLjtpDWOkA https://www.youtube.com/watch?feature=player_embedded&v=U4YHsaBlMUs

Why do we do it? Development of social skills Cultural transmission – It’s about the how, not the why. Normative learning – fitting in to our social group Kenward, et al. – simply ask children why they are overimitating Demonstrate irrelevant and unnecessary actions similar to previously mentioned studies. Then, ask the child how they will retrieve prize. When the children described the reason for performing necessary actions, they replied that they “needed to” or it was required to retrieve the object. When the children described the reason for performing the unnecessary actions, they replied that they were “supposed to” or that they weren’t sure. Findings: Children replicate unnecessary actions because they are following norms, not because they code the action as causal to achieve the goal.

Do other primates overimitate? Horner and Whiten’s research indicates that chimpanzees do not overimitate. When presented with irrelevant and unnecessary actions, chimps only produce goal directed behaviors. It’s not that hard to open a box!

Do other primates overimitate? Horner and Whiten – Chimps vs. Kids Children (3-4 yo) and young, wild-born chimps Two conditions: opaque box and clear puzzle box Experimenter would insert stick in to opaque box (irrelevant action). It was not clear to either chimps or children whether this action was relevant or not. When stick was inserted in the clear box, it was obvious that this action was irrelevant to all participants. Findings: Chimps imitated actions that seemed causal. However, irrelevant actions were not imitated! Chimps would use more efficient strategy to open the clear box. https://youtu.be/6zSut-U1Iks

Do other primates overimitate? Horner and Whiten Criticisms: Experimenters demonstrated each condition three times. Was this interpreted as a verbal mandate to children to “do it like so” leading to their high rates of overimitation? Horner and Whiten argue it was necessary to guarantee the chimps were paying attention. What does this mean? Are we being outsmarted by our less sophisticated cousins? Chimps adopts a more efficient strategy because their only focus is the goal: retrieve the prize! Children, on the other hand, view situation as learning experience, assign importance to each action, and although they may not understand why irrelevant actions may be important, they understand that it is a necessary step to achieve their goal.

Why do you care? Cartmill and Brown “Humans are the only terrestrial mammals that imitate sounds, and the only animal that imitates the things we see.” Art, dance, even language begin with imitation, specifically in mother-infant pairs. Imitations  Language  Social norms However, social norms lead to overimitation - imitating actions even though they are recognized as irrelevant or unnecessary

Real world application: Can you think of a time when you have exhibited or witnessed overimitation in your social group?