BACKGROUND Kinship theory (or the genomic conflict hypothesis) proposes that the phenotypic effects of genomic imprinting arise from conflict between paternally and maternally inherited alleles. A prediction arising for social behaviour from this theory is that imbalance in this conflict resulting from a deletion of a maternally imprinted gene, as in Angelman syndrome (AS), will result in a beh...

Infants over one month of age tend to produce two types of smiling during especially positive social interactions, Duchenne smiles involving cheek raising and open-mouth smiles. Little is known, however, about the prevalence, frequency, duration and organization of these smiles among neonates. Twenty-five full-term, healthy neonates (12 female) were videotaped during six minutes of sleep. Smile...

US social psychologists have found that there is a gender difference for use of a smiling facial expression. A replication was found in France where numeric photographs of student-yearbooks were examined to observe whether the student smiled or not. Results shown that women were more likely to smile and to do so more fully. These results where congruent with previous research conduct in United ...

Angelman syndrome is a neurogenetic disorder associated with unique behaviors and characteristics, including an unusually happy expression, inability to speak, ataxia, mental retardation, and abnormal EEG. Previous research has suggested that smiling and laughing behaviors in Angelman syndrome are inappropriate, excessive, and dissociated from contextual events. In the present study, the variab...

The present paper reports on results of a study investigating changes of lip features, larynx position and acoustics caused by smiling while speaking. 20 triplets of words containing one of the vowels /a:/, /i:/, /u:/ were spoken and audiovisually recorded. Lip features were extracted manually as well as using a 3D motion capture technique, formants were measured in the acoustic signal, and the...