When it comes to getting intimate, foreplay is just the start, and now a new study has concluded that it’s what comes after sex that matters most to women.

The research, published in The Journal of Sexual Medicine, polled more than 5,600 women in Japan, and found that almost half of the respondents (49%) wanted a longer continuation of intimacy with their partner after sex.

That compared with 44 percent who said they wanted longer foreplay and 38 percent of women who said they wanted longer actual intercourse.

Despite this finding, 38.8 percent of respondents said that they had never discussed their favourite sex practises with their partner.

The study summed up that:

Women consider longer foreplay and after play to be more important

and suggested:

[W]omen would benefit by being more forthright in expressing their sexual desires to their partners.

Additionally, more than 30 percent of the women surveyed also rated their partner’s performance in bed as either “very selfish” (6.9%), or “selfish” (25.5%).

Posted by Jonathan as Sociology at 3:47 PM BST

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In new research from the ‘Institut fuer Kondom-Beratung‘, 10,477 men from 25 European Union member countries were asked to measure the length and girth of their manhood in its erect state.

The results were that the survey found men around Europe vary dramatically, with the French, famous for their letters, who measured up with the longest and thickest penis, whilst Greeks had the smallest average measurements.

Jan Vinzenz Krause, the institute’s director, who caused a stir two year ago with a prototype “spray-on condom”, refused to comment about how honest he thought the Frenchmen had been in reporting the data. Only noting “The purpose of the survey was to educate teenagers about the importance of effective contraception.”

Posted by Jonathan as Anthropology, Sociology at 12:05 AM BST

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The usefulness of sex, according to an intriguing new theory of evolutionary biology, may be its ability to promote genes that play well with many other partners, rather than just those that shine with one specific set of genes.

This idea of genetic mixability, described in the journal Proceedings of the National Academy of Sciences hits on the difficulties that Evolutionary biologists have had in understanding the role of sex in population genetics and Darwin’s survival-of-the-fittest mantra.

Lead author Adi Livnat, a Miller Institute post-doctoral fellow based at UC Berkeley’s Department of Electrical Engineering and Computer Sciences said:

During the past century, it has often been assumed that sexual reproduction should somehow facilitate the increase in fitness under natural selection, leading to the ‘best’ combinations of genes. But no agreement has been reached on whether and how this could really work. One might think, for example, that by bringing together genes from different individuals, sexual reproduction could create a very successful combination of genes. But just as sexual reproduction will create that very successful combination of genes, it could also break it down in the next generation.

That sex can actually impede the increase in the fitness of the population raises the question of how it could remain the dominant form of reproduction across all manner of species, when the fact remains that sexual reproduction (the merging of genes from different individuals to create genetically unique offspring) is the reproductive method of choice from humans to plants to many fungi. So, this form of reproduction must be doing something right in terms of evolution.

Thinking laterally, instead of making the standard assumption that sexual reproduction increases the average fitness of a population, the researchers came up with a new measure they call “mixability” to represent a gene’s ability to perform well across many different combinations.

They tested the mixability measure in a number of scenarios, within a well-established population-genetic framework and found that if the goal is to maximize fitness by finding a particularly good combination of genes, asexual reproduction – which increases a population’s numbers at a much faster rate than sexual reproduction – works very well.

In contrast, sexual reproduction, through the process of recombination and segregation of chromosomes, strongly favours genes that work well in many different variations rather than any one good combination. In that view, the authors wrote, alleles of the same gene compete with each other based upon how well they perform on average rather than how well they perform in any one specific combination.

Co-author Marcus Feldman, Professor of Biology at Stanford University, and a world-renowned theorist in evolutionary biology said:

It’s important to note that during the process of evolution, the mixability value increases, though it doesn’t increase all the time. The approach we take is different from usual because we’re interested in Evolutionary transience, and in the long run, our mixability value may actually decrease because too much variability is lost from the population.

Even so, sexual reproduction has a great advantage for mixability compared with asexual reproduction, according to the models used in the paper.

Livnat started thinking about this problem in discussions with co-author Christos Papadimitriou, Professor of computer sciences at the University of California, Berkeley, and a leading computer theorist whose research includes optimization algorithms. Such programming is widely used to find best outcomes in applications such as computer networks, transportation planning and financial models.

The researchers explained that of the two main techniques for optimization programming, the first, known as simulated annealing, solves problems using a process analogous to asexual reproduction, whilst the second, known as genetic algorithms, is inspired by sexual reproduction. Genetic algorithms should theoretically be the more efficient of the two techniques for finding the best solutions to a problem because they mimic an approach that is so dominant in nature. However, it turns out that genetic algorithms often perform no better than simulated annealing.

Professor Papadimitriou said:

We were trying to figure out why an algorithm that mimics a good idea in nature was not coming up with better results. It dawned on us that what sexual reproduction is doing is not maximizing fitness, but doing something more subtle. It is bringing about genetic variants that perform well across many possibilities in connection with a great variety of genetic partners. If a particular gene variant can do well with many other alleles, not just a highly specialized variant, evolution is advanced.

The researchers noted that when the human genome was sequenced in 2003, there was surprise that humans didn’t possess far more genes than other species. It turns out that how those genes are combined may be a critical factor in distinguishing humans from other species, supporting the importance of flexibility over fitness.

Feldman, who has studied the evolution of sex and recombination for more than three decades, said he expects this new theory to trigger much debate among his peers, adding:

This problem of understanding sex will go on being one of the central issues in evolution.

Posted by Jonathan as Biology, Sociobiology at 12:53 AM BST

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Researchers, based at the Institute of Psychiatry, King’s College London have been analysing archived data from former US soldiers who underwent intensive testing for intelligence, detailed medical examinations and provided semen samples.

The results, published in the journal Intelligence showed that in the men who performed better on intelligence tests, total sperm count was higher, as well as sperm concentration and motility. This suggests that in our ancestors, intelligence and sperm quality were linked, so intelligent men were more likely to reproduce.

It might be argued that brighter people would be less likely to smoke, and more likely to take exercise, both of which are known to impact on mental performance. But, even when lifestyle factors such as body mass index, use of alcohol, tobacco, marijuana, and hard drugs were taken into account, there was still a statistically significant correlation between intelligence and sperm quality.

Lead researcher Dr Rosalind Arden said:

We are not trying to say that under modern conditions intelligent men are going to have more children.

We wanted to test the idea that intelligence is favoured by natural selection.

We look forward to seeing if the results can be replicated in other data sets, with other measures of intelligence and other measures of physical health that are also strongly related to evolutionary fitness.

Dr Allan Pacey, Senior Lecturer in Andrology at the University of Sheffield commented:

The fact that it’s possible to detect a statistical relationship between intelligence and semen quality in adult men probably says more about the co-development of brain and testicles when the man was in his mother’s womb, and therefore how well they both function in adult life, rather than suggesting that playing Sudoku can somehow stimulate more sperm to be produced.

Posted by Jonathan as Biology, Sociobiology at 11:07 PM BST

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In 1956, Denham Harman proposed the theory of ‘oxidative stress‘; in which he claimed that ageing is caused by a build-up of molecular damage to cells, from the actions of reactive forms of oxygen such as superoxide.

These free radicals (oxygen molecules with an imbalance of protons to electrons) are created as by-products of cells metabolising sugars to release energy – So, the Diet and Beauty industry claims that Antioxidants such as vitamins C and E supposedly work to mop these up, thus minimising potential cell damage.

The oxidative stress theory has dominated the field of ageing research ever since it was proposed, but now, a recent study published in the journal Genes and Development, suggests that the idea is probably incorrect and that superoxide is not a major cause of ageing.

David Gems, of University College London, and colleagues at the Institute of Healthy Ageing studied the action of key genes involved in removing superoxide from the bodies of the nematode worm Caenorhabditis elegans, a commonly used organism in research into ageing. By manipulating the worm’s genes, they were able to control the nematode’s ability to ‘mop up’ surplus superoxide and limit potential damage caused by free radicals. This modification should have given the GM nematodes an advantage over normal nematodes, in terms of ageing and lifespan.

However, contrary to the results predicted by the free radical theory of ageing, the researchers found that the lifespan of the worms was relatively unaffected by their ability to tackle the surplus superoxide. So, these findings, combined with similar recent findings from the University of Texas, using mice, suggest that the oxidative stress theory is incorrect.

Dr Gems, who led the study, noted that molecular damage was probably caused by numerous different chemicals within the cell, and went on to say:

Our results spectacularly failed to support the view of the free radical theory.

The fact is that we don’t understand much about the fundamental mechanisms of ageing – the free radical theory has filled a knowledge vacuum for over 50 years now, but it doesn’t stand up to the evidence.

A healthy, balanced diet is very important for reducing the risk of developing many diseases associated with old age, such as cancer, diabetes and osteoporosis, but there is no clear evidence that dietary antioxidants can slow or prevent ageing. There is even less evidence to support the claims of most anti-ageing products.

Dr Alan Schafer, Head of Molecular and Physiological Sciences at the Wellcome Trust, who funded the research, said:

With increasing lifespan comes greater exposure and vulnerability to the ageing process. Research such as this points to how much we have to learn about ageing and the importance of understanding the mechanisms behind this process.

This new study will encourage researchers to explore new avenues in ageing research.

Posted by Jonathan as Biochemistry, Biology at 11:00 PM BST

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It has been suggested that people who make an effort to speak to strangers (as a Seductionist might), have fewer people in their social network compared to people who don’t make that effort.

We’d like to test this theory – so, being honest (your identity always stays secret), thinking carefully, and including all your friends, relatives, acquaintances and work colleagues etc.

Posted by Jonathan as Polls & Surveys at 2:00 AM BST

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A couple of years back, when the Serious Fraud Office (SFO) launching an investigation into accounting irregularities at SSL International (the parent company of Durex condoms), I thought that might just be the Accountants massaging the figures.

The Scientists that work at Durex would surely be more interested in seeking truths and advancing knowledge than making money. After all, Durex is generally considered one of the world’s leading prophylactic brands, and the company is responsible for helping its customers prevent unwanted pregnancies and avoid a multitude of nasty and potentially fatal sexually transmitted infections.

So, we were quite surprised to receive a missive from PR company McCann Erickson, tipping us off to a new product from Durex – a female masturbation gel – which allegedly encourages blood flow to a woman’s clitoris, and supposedly makes it more sensitive.

I suspect that the product is simply a small amount of Capsaicin in a solution of liquid Paraffin, but McCann Erickson didn’t go into too much detail, and were more keen to link to the ‘Durex Sexual Wellbeing Global Survey’, also pointing out that using their clients product, 79% of British women achieved orgasm.

Impressive stuff you might say. But, looking at the above survey, Quality Control has obviously slipped up at the condom company, because Poland is quite clearly listed twice. A schoolboy error; and not something that one should expect to find in a piece of purportedly serious research.

This leads to a second query – 79% of British women achieved an orgasm using the product, but unfortunately, Durex and McCann Erickson omitted to give any measure of reliability (such as probable error or standard error), which devalues the statistic somewhat. However, what would be very much more useful would be a comparison telling us how many British women achieved an orgasm without using the product.

This got me wondering; whilst men are pretty much guaranteed an orgasm from masturbation, I know that orgasm can be more difficult for women, but exactly how likely are women to achieve orgasm? If the answer was in the region of 79%, then Durex/McCann Erickson’s claims would be rather less impressive.

It seems the figure is actually quite elusive, and the best I could find through Google was Clitical.com, where a list of orgasm ‘facts’ claimed that “One study found that only 7.7 percent of women whose lovers spent 21 minutes or longer on foreplay failed to reach orgasm” thus implying that 92.3% succeeded to reach orgasm, although Clitical failed to mention which study they refer to. The same webpage also asserts that (for females) 95% of masturbation sessions result in orgasm, but again, the author doesn’t mention any study this time, so that figure might just be just his girlfriend’s experience, for all we know.

Whilst there might not be a lot of data available for orgasm through female masturbation, scientific researchers have certainly been pretty busy over the years collecting information about female orgasms through intercourse. And, it seems that from a sample of 800 married couples, Terman (1938) reported that 8.3% never achieved orgasm through intercourse, whilst Chesser (1956), using a sample of 2,000 married English women, reported that 5% never achieved orgasm through intercourse. Fisher (1973) studied 300 married American women, of whom 5% reported never achieved orgasm through sex; then using a sample of about 700 white American women, Hunt (1974) reported that 7% rarely or never achieve orgasm. Finally, and most impressively, Tarvis and Sadd (1977) reported that from a sample of 100,000 American women, who responded to a Redbook magazine questionnaire, 7% reported never achieving orgasm through coitus.

McCann Erickson’s original message asked what we thought; and despite contacting them, pointing out the errors and requesting clarification some while back, neither McCann Erickson nor Durex were prepared to respond again.

Posted by Jonathan as Miscellaneous at 11:55 PM BST

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