Kyudai News No26 page 14/28

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Kyudai News No26

13 Kyudai News No.26 ommunication is crucial for humans, one of themost social species on the planet*1. However, itis still unclear how “human unique socialminds”, which enable such features ascooperative or empathetic biases of the individual, haveemerged and transformed through evolution. Naturalscientific studies on behavioral development in infancy isone of the ways to approach this enigma.Studies in Developmental Psychology have examinedpreverbal infants’ communicative expressions in varioussocial contexts to clarify how our communication emergesand transforms over the course of development, especiallysince the turn of this century. The results have indicatedthat infants seem to understand something about others’goals and intentions, and have some levels of the prosocialmotives for interacting with others *2. For example,12-month-old infants point more frequently to provideinformation to another person who is looking for an objectwithout particular knowledge about the object’s location, ascompared to situations in which he/she has knowledge ofthe object’s location *3. However, most of the studies wereprimarily concerned about comprehensive aspects ofinfants’ communication (i.e., a response elicited by theexperimenter’s particular actions) *4. Considering theinteractive process of communication *1 and the culturaltransmission *5, the development of spontaneous productionalso has to be examined, in order to understand the originof human communication. The current study focused onthis topic, and suggested that the infants in the first half oftheir second year of life already have a tendency tospontaneously inform for the other, on the basis of somelevels of understanding about the other’s knowledge andattentional states.Research SummaryProcedureTwo experiments were conducted and each infantparticipated in one of the two experiments. Thirty-two13-18 months old infants and their caretakers (finalsamples, 16 each for Exps. 1 and 2), who registered asmembers of the volunteer panel for developmentalpsychological research in Kyushu University, participatedin the study. The experiments were performed in theColabo-Station II in Maidashi-campus, Kyushu University.Each experiment included six trials as the maximum and atrial consisted of two phases (Figure 1).Experiment 1In the Shared Experience Phase, both the participant andthe Experimenter 1 experienced (played with) an object(Familiar to E1), and the participant experienced a secondobject (New to E1) while the Experimenter 1 was absent.The plays lasted for one minute, respectively, in a randomorder. In the following Pointing Phase, the participant wasseated on his/her mother’s lap, facing the Experimenter 1,and the same two objects from the Shared ExperiencePhase were presented side-by-side behind the experimenterin a random order. The participants’ looking time towardsthe objects in the Shared Experience Phase andspontaneous pointing in the Pointing Phase were analyzedfrom video footage (Figure 2).Experiment 2In order to ensure that the infants’ pointing behaviorobserved in Experiment 1 reflected the shared experiencebetween the infants and the experimenter, a newexperimenter (E3) was introduced in the Pointing Phase,who was not involved in the Shared Experience Phase andthus had no experience shared with the infant regardingeither object. All other procedures were identical to thosein Experiment 1.*Experimenter 2 was an assistant who handled the objects(e.g., removing the objects from a container in the SharedExperience Phase and controlling object presentation in thePointing Phase).ResultsExperiment 1The main results showed that infants initially pointed to theNew to E1 object on 66% of all the trials that includedpointing on average, and a one-sample t-test showed thatthis was significantly above chance (50%) (p = .005). Theseresults demonstrate that despite the lack of difference in theIn Search of the Developmental Human Communication CFigure 1. ProcedureMethods(Exp1,2)Figure 2. Sample of infantOsspontaneous pointing in the PointingPhase.Spontaneous pointing in thePointing Phase.Highlight of Recent Research