We propose that intentionally produced humor is a form of communication that evolved to broadcast information about the self and to obtain information about others by honestly signaling the fact of shared common knowledge. According to this model, humorous utterances and acts are encrypted in the sense that what makes the joke funny is not merely its surface content, but a relationship between the surface content and one or more unstated implicatures which are known by both the sender and the receiver. It is the non-random nature of the match between this unstated knowledge and the surface content which provides evidence that the producer possesses that knowledge, and that those who appreciate the joke do as well, thus rendering humor a means of assessing shared underlying knowledge, attitudes, and preferences. We present evidence from two experimental studies of humor evaluation in support of the encryption theory.
When communicating with infants, caregivers often modulate their speech in an effort to make their communicative and informative intentions more clear. Infant-directed (ID) speech differs acoustically from adult-directed (AD) speech, and systematically varies according to different kinds of intentions. This way of speaking to infants is thought to be a species-specific adaptation, as research has documented highly similar patterns in ID speech across a variety of cultures. A recent study has also shown that people from an indigenous non-Western culture (Shuar of Amazonian Ecuador) can reliably discriminate ID speech from AD speech in a language they do not speak, and distinguish between four different intention categories (prohibition, attention, comfort, and approval). The current research attempted to replicate this finding in a traditional African population, the Turkana of northwestern Kenya. In three experiments, we found that Turkana adults were able to discriminate between ID and AD speech produced in English by American mothers, and they could also distinguish between several intention categories in both ID and AD speech. Signal detection analysis revealed that ID speech was marginally more discriminable than AD speech, but overall rate of intention recognition was similar across speech types. These results partially support the hypothesis that ID speech is universally recognizable due to the formfunction relationship between acoustic signals and their communicative purpose, but there were differences in performance between Turkana and Shuar that merit further investigation.
Previous research on children's understanding of social contracts has shown that children are able to identify violations of social contracts from an early age, that they attribute negative feelings including anger to victims of contract violations, and that attributions of negative (moral) feelings to violators increase with age. This study examines two questions that have not been systematically investigated in prior work. First, do children attribute specific types of negative emotion, guilt and anger, to violators and victims of social contracts, and do these attributions change with age? Second, do children's attributions of guilt and anger depend on the social roles of the parties in the contract, including parents and offspring, siblings, and friends? Using a bilateral social contract scenario with first and fourth graders, we found that children in both age groups were able to identify contract violations, and attributed guilt to violators and anger to victims of social contract violations. Although anger and guilt attributions increased with age, they were high across both ages, and relatively unaffected by type of role relationship. These results suggest that children understand the moral emotions associated with violations of social contracts.