Darwin discusses why different muscles are brought into action under different emotions and how particular animals have adapted for association with man.

While separate pieces of research found parents offer toddlers cues to express that they are joking and pretending, and that toddlers and preschoolers understand intentions to joke and pretend, it is not yet clear whether parents and toddlers consider joking and pretending to be distinct concepts. This is important as distinguishing these two forms of non-literal acts could open a gateway to understanding the complexities of the non-literal world, as well as the complexities of intentions in general. Two studies found (...) parents offer explicit cues to help 16- to 24-month-olds distinguish pretending and joking. Across an action play study and a verbal play study parents showed more disbelief and less belief through their actions and language when joking versus pretending. Similarly, toddlers showed less belief through their actions, and older toddlers showed less belief through their language. Toddlers' disbelief could be accounted for by their response to parents' language and actions. Thus, these studies reveal a mechanism by which toddlers learn to distinguish joking and pretending. Parents offer explicit cues to distinguish these intentions, and toddlers use these cues to guide their own behaviors, which in turn allows toddlers to distinguish these intentional contexts. (shrink)

The laugh- and/or smile-evoking potency of laughter was evaluated by observing responses of 128 subjects in three undergraduate psychology classes to laugh stimuli produced by a “laugh box.” Subjects recorded whether they laughed and/or smiled during each of 10 trials, each of which consisted of an 18-sec sample of laughter, followed by 42 sec of silence. Most subjects laughed and smiled in response to the first presentation of laughter. However, the polarity of the response changed quickly. By the 10th trial, (...) few subjects laughed and/or smiled, and most found the stimulus “obnoxious.” Although other research has described canned-laughter effects, it did not consider the hypothesis confirmed here, that laughter itself evokes laughter, perhaps by activating a laughter-specific auditory-feature detector. This result is relevant to the neurological basis of social communication, human ethology, and theories of speech production and perception. (shrink)