A Brief Survey on Animal Behavior Studies

This is a living survey of animal behavior studies; entries will be added over time.

This blog post offers a brief survey of two questions:

What. What behaviors — and more importantly, what cognitive skills — are observed in which species?
How. How are these cognitive skills tested, and what do the criticisms say?

Social Skills

Vicarious Emotion Learning

References

Empathy and pro-social behavior in rats. Science (2011)

Pro-social behavior in rats is modulated by social experience. eLife (2014)

The roots of empathy: through the lens of rodent models. Neuroscience & Biobehavioral Reviews (2017)

What behavior. Rats free trapped cage mates and choose to help even when chocolate is available. Their helping is governed by strain familiarity rather than genetic relatedness: a rat will help strangers from the strain it grew up with, rather than a strain that is more closely related genetically.

Mechanism. Rats perceive a conspecific’s distress → this triggers affective arousal (shared emotional state) in the observer → that shared distress is aversive → which motivates prosocial action to end it. They don’t do so for intrinsic motivation of interacting with others because even after the caged mate will be sent into a separate room after being freed, rats will go and free it anyway.

Cognitive skills. Vicarious emotion learning and affective arousal. Learning about danger by watching someone else get hurt is far safer than learning by getting hurt yourself. It points to a biologically ancient mechanism for the social transmission of survival-relevant information.

Theory of Mind: Actors Act According to False Belief

References

Great apes anticipate that other individuals will act according to false beliefs. Science (2016)

A test of the submentalizing hypothesis: apes’ performance in a false belief task with inanimate controls. Communicative & Integrative Biology (2017)

Great apes use self-experience to anticipate an agent’s action in a false-belief test. PNAS (2019)

Great apes distinguish true from false beliefs in an interactive helping task. PLOS ONE (2017)

Great apes, while watching videos, anticipatorily looked where an actor falsely believed a hidden object to be — the first evidence apes might track others’ false beliefs.

Alternative explanations are ruled out.

Submentalizing. For instance, apes simply memorize spatial relationship between the green shirt and the object. However, when the green shirt is replaced by a green object, apes gaze randomly.

Behavior-rule account. For instance, apes simply predict “agents search where they last looked”. The experiment setting for rebuttal: object hidden in box 1 → actor goes behind barrier → object moved to box 2 → object removed entirely from the scene. Apes first experience the barrier by themselves, one group can see through the object (transparent barrier) and another group can’t. The first group gazes randomly, and the second group gazes according to false belief. Therefore, apes at least reasone on “belief-like states” — “where did the agent last encounter the object?”

Ignorance-based rule. Apes don’t just look in the right direction — they actively act on their understanding of another’s beliefs. Apes help agents to retrieve the hidden object. Apes do this not because they think the experimenter is ignorant (doesn’t know where the object is). Indeed, when the experimenter never saw the object placed in any box and thus he has no belief about its location, apes gaze randomly.