The origins of vocal learning: New sounds, new circuits, new cells

We do not know how vocal learning came to be, but it is such a salient trait in human evolution that many have tried to imagine it. In primates this is difficult because we are the only species known to possess this skill. Songbirds provide a richer and independent set of data. I use comparative data and ask broad questions: How does vocal learning emerge during ontogeny? In what contexts? What are its benefits? How did it evolve from unlearned vocal signals? How was brain anatomy altered to enable vocal learning? What is the relation of vocal learning to adult neurogenesis? No one has described yet a circuit or set of circuits that can master vocal learning, but this knowledge may soon be within reach. Moreover, as we uncover how birds encode their learned song, we may also come closer to understanding how we encode our thoughts.     

Skills,historical disclosing,and the end of history: A response to our critics

We appreciate the thoughtful responses we have received on ‘Disclosing New Worlds’. We will respond to the concerns raised by grouping them under three general themes. First, a number of questions arise from lack of clarity about how the matters we undertook to discuss ‐ especially solidarity ‐ appear when one starts by thinking about the primacy of skills and practices. Under this heading we consider (a) whether we need more case studies to make our points, and (b) whether national and other solidarities require willingness to die for the values that produce that solidarity. Second, we take up questions concerning the historical character of the skills of entrepreneurs, virtuous citizens, and culture figures. Here we shall (a) emphasize how we distinguish ourselves from earlier writers on these subjects, (b) consider essentialism, relational identities, and exclusion, (c) answer a number of Habermasian concerns raised by Hoy, (d) speak to Taylor's concern regarding the contingency of solidarity and forgetting, and (e) take up Grant's objection that we are both formalists and relativists. Third, we shall take up the concern, raised mostly by Borgmann, that historical disclosing, that is to say history as the West has known it, is over, and that now all that can be done by those who transform the practices is to make them more and more technological.     

Experimental evidence for action imitation in killer whales (Orcinus orca)

Comparative experimental studies of imitative learning have focused mainly on primates and birds. However, cetaceans are promising candidates to display imitative learning as they have evolved in socioecological settings that have selected for large brains, complex sociality, and coordinated predatory tactics. Here we tested imitative learning in killer whales, Orcinus orca. We used a ‘do-as-other-does’ paradigm in which 3 subjects witnessed a conspecific demonstrator’s performance that included 15 familiar and 4 novel behaviours. The three subjects (1) learned the copy command signal ‘Do that’ very quickly, that is, 20 trials on average; (2) copied 100 % of the demonstrator’s familiar and novel actions; (3) achieved full matches in the first attempt for 8–13 familiar behaviours (out of 15) and for the 2 novel behaviours (out of 2) in one subject; and (4) took no longer than 8 trials to accurately copy any familiar behaviour, and no longer than 16 trials to copy any novel behaviour. This study provides experimental evidence for body imitation, including production imitation, in killer whales that is comparable to that observed in dolphins tested under similar conditions. These findings suggest that imitative learning may underpin some of the group-specific traditions reported in killer whales in the field.     

The Relationship Between Sexual Orientation and Gender Identification Among Males in a Cross-Cultural Analysis in Brazil, Turkey and Thailand

This study measures and compares the level of congruency between male sexual orientation and gender identification using the Kinsey Scale in three cultures: Brazil (Florianópolis), Turkey (Istanbul) and Thailand (Bangkok) with social class as the control mechanism. Quantitative techniques are utilized in comparing the self-evaluation of sexual orientation and gender identification among young men with same-sex, opposite-sex and both-sex orientations or behaviors. Results: In all three cultures, homosexuals were much more likely than bisexuals or heterosexuals to enjoy receiving anal sex and performing fellatio. Bisexual and heterosexual men, as expected, reported enjoying vaginal penetration and cunnilingus more than homosexual men. Same-sex oriented male self-evaluations of homosexual orientation and feminine gender identification scored similarly on the Kinsey Scale (0–6) in all three countries. These data support the traditional identity trichotomy used in the field: homosexuality, bisexuality and heterosexuality. When controlling for nationality only small differences were found amongst the participants; however, social class or level of education did have a significant effect on the relationship between self-evaluation of sexual orientation and gender identification.