Imitative learning

Imitative learning is a type of social learning whereby new behaviors are acquired via imitation. Imitation aids in communication, social interaction, and the ability to modulate one's emotions to account for the emotions of others, and is "essential for healthy sensorimotor development and social functioning". The ability to match one's actions to those observed in others occurs in humans and animals; imitative learning plays an important role in humans in cultural development. Imitative learning is different from observational learning in that it requires a duplication of the behaviour exhibited by the model, whereas observational learning can occur when the learner observes an unwanted behaviour and its subsequent consequences and as a result learns to avoid that behaviour.

Imitative learning in animals

On the most basic level, research performed by A.L. Saggerson, David N. George, and R.C. Honey showed that pigeons were able to learn a basic process that would lead to the delivery of a reward by watching a demonstrator pigeon. A demonstrator pigeon was trained to peck a panel in response to one stimulus (e.g. a red light) and hop on the panel in response to a second stimulus (e.g. a green light). After proficiency in this task was established in the demonstrator pigeon, other learner pigeons were placed in a video-monitored observation chamber. After every second observed trial, these learner pigeons were then individually placed in the demonstrator pigeon's box and presented the same test. The learner pigeons displayed competent performance on the task, and thus it was concluded that the learner pigeons had formed a response-outcome association while observing. However, the researchers noted that an alternative interpretation of these results could be that the learner pigeons had instead acquired outcome-response associations that guided their behavior and that further testing was needed to establish if this was a valid alternative.

A similar study was conducted by Chesler, which compared kittens learning to press a lever for food after seeing their mother do it to kittens who had not. A stimulus in the form of a flickering light was presented, after which the kitten has to press a lever in order to obtain a food reward. The experiment tested the responses of three groups of kittens: those that observed their mother's performance first before attempting the task, those that observed a strange female's performance, and those that did not have a demonstrator and had to complete it through trial and error (the control group). The study found that the kittens that observed their mother before attempting the task acquired the lever-pressing response faster than the kittens that observed a strange female's response. The kittens conducting the task through trial and error never acquired the response. This result suggests that the kittens learned from imitating a model. The study also speculates whether the primacy of imitative learning, as opposed to trial end error, was due to a social and biological response to the mother (a type of learning bias).

Whether true imitation occurs in animals is a debated topic. For an action to be an instance of imitative learning, an animal must observe and reproduce the specific pattern of movements produced by the model. Some researchers have proposed evidence that true imitation does not occur in non-primates, and that the observational learning exhibited involves less cognitively complex means such as stimulus enhancement.

Chimpanzees are more apt to learning by emulation rather than true imitation. The exception is encultured chimpanzees, which are chimpanzees raised as if they were children. In one study by Buttelman et al, encultured chimpanzees were found to behave similarly to young children and imitate even those actions that were non instrumental to achieving the desired goal. In other studies of true imitation, encultered chimpanzees even imitated the behaviour of a model some time after initially observing it.

Imitative learning in humans

Imitative learning has been well documented in humans; they are often used as a comparison group in studies of imitative learning in primates. A study by Horner and Whiten compared the actions of (non-encultured) chimpanzees to human children and found that the children over-imitated actions beyond necessity. In the study, children and chimpanzees between the ages of 3-4 were shown a series of actions to open an opaque puzzle box with a reward inside. Two of the actions were necessary to open the box, but one was not, however this was not known by the subjects. A demonstrator performed all three actions to open the box, after which both the chimpanzees and the children attempted the task. Both the children and the chimpanzees copied all three of the behaviours and received the reward inside of the box. The next phase of the study involved a transparent box instead of the opaque box. Due to the transparency of this box, it could clearly be seen that one of the three actions was not necessary to receive the reward. The chimpanzees did not perform the unnecessary action and only performed the two actions necessary to achieve the desired goal. The young children imitated all three actions, despite the fact that they could have selectively ignored irrelevant actions.

There is also evidence that humans are discerning in which actions to imitate, but that they differ to chimpanzees in that they do not partake in goal-based emulation but rather rational imitation. In a study by Gergely, children saw a demonstration of an adult turning on a light with their forehead, despite their hands being free. After this demonstration, a majority of the children copied the action and turned the light on with their forehead. They then saw a second demonstration, where the model had their hands bound by having a blanket wrapped around them. After observing this demonstration, most of the children did not replicate it by pressing their forehead on the light, choosing to use their hand instead. The study suggests that children are rational in their discernment of which actions to copy. In the first case, where the demonstrator's hands are free, the study suggests the children are imitating for a non-instrumental reason. In the second case, where the children could see that the model was only performing this action because their hands were bound, the children chose to not to imitate it strictly because their own hands were not bound, and this seemed to be the only (instrumental) reason why the model was using their forehead.