Beware of who you kiss

Beware of who you kiss

Forensic Sci Int Genet. 2013 Jan;7(1):124-8. doi: 10.1016/j.fsigen.2012.07.007. Epub 2012 Aug 20.

Prevalence and persistence of male DNA identified in mixed saliva samples after intense kissing.

Kamodyová N, Durdiaková J, Celec P, Sedláčková T, Repiská G, Sviežená B, Minárik G.

Abstract

Identification of foreign biological material by genetic profiling is widely used in forensic DNA testing in different cases of sexual violence, sexual abuse or sexual harassment. In all these kinds of sexual assaults, the perpetrator could constrain the victim to kissing. The value of the victim's saliva taken after such an assault has not been investigated in the past with currently widely used molecular methods of extremely high sensitivity (e.g. qPCR) and specificity (e.g. multiplex Y-STR PCR). In our study, 12 voluntary pairs were tested at various intervals after intense kissing and saliva samples were taken from the women to assess the presence of male DNA. Sensitivity-focused assays based on the SRY (single-copy gene) and DYS (multi-copy gene) sequence motifs confirmed the presence of male DNA in female saliva after 10 and even 60min after kissing, respectively. For specificity, standard multiplex Y-STR PCR profiling was performed and male DNA was found in female saliva samples, as the entire Y-STR profile, even after 30min in one sample. Our study confirms that foreign DNA tends to persist for a restricted period of time in the victim's mouth, can be isolated from saliva after prompt collection and can be used as a valuable source of evidence.

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Assortative mating for height in the UK

Assortative mating for height in the UK

PLoS ONE 8(1): e54186. doi:10.1371/journal.pone.0054186

Are Human Mating Preferences with Respect to Height Reflected in Actual Pairings?

Gert Stulp et al.

Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK) and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i) assortative mating (r = .18), (ii) the male-taller norm, and, for the first time, (iii) for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men) prefer large height differences with their partner, whereas tall women (and short men) prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly.

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Male-Female differences in chess achievement

Male-Female differences in chess achievement

This paper looks at relative achievement of men and women in chess to test whether or not male-female differences in achievement diminished over time. The main conclusion is that they have remained fairly constant. In my opinion, this indicates either that (i) men are more likely to have exceptional levels of ability than women, or (ii) women are less motivated to devote the necessary time and effort to become really good chess players, or both.

Journal of Biosocial Science (2004)
DOI 10.1017/S0021932004006868

ARE GENDER DIFFERENCES IN HIGH ACHIEVEMENT DISAPPEARING? A TEST IN ONE INTELLECTUAL DOMAIN
ROBERT W. HOWARD

Abstract
Males traditionally predominate at upper achievement levels. One general view holds that this is due only to various social factors such as the ‘glass ceiling’ and lack of female role models. Another view holds that it occurs partly because of innate ability differences, with more males being at upper ability levels. In the last few decades, women have become more achievement focused and competitive and have gained many more opportunities to achieve. The present study examined one intellectual domain, international chess, to quantify its gender differences in achievement and to see if these have been diminishing with the societal changes. Chess is a good test domain because it is a meritocracy, it has objective performance measures, and longitudinal data of a whole population are available. Performance ratings overall and in the top 10, 50 and 100 players of each sex show large gender differences and little convergence over the past three decades, although a few females have become high achievers. The distribution of performance ratings on the January 2004 list shows a higher male mean and evidence for more male variation, just as with traits such as height. Career patterns of players first on the list between 1985 and 1989 show that top males and females entered the list at about the same age but females tend to play fewer games and have shorter careers. In this domain at least, the male predominance is large and has remained roughly constant despite societal changes.