Archive for December, 2010

Sex at Dawn

Tuesday, December 28th, 2010

Book review: Sex at Dawn: The Prehistoric Origins of Modern Sexuality by Christopher Ryan and Cacilda Jetha.

This book makes a strong case that pre-agricultural humans were very far from monogamous, much like Chimps and Bonobos. It’s often convincing, but sometimes biased by ideology.

Some of the evidence comes from the difficulty that humans have being monogamous now, and the under-reported satisfaction of cultures that encourage egalitarian sharing of mates (including WWII pilots). Some stronger evidence comes from the size of our genitalia, and the promiscuous, egalitarian sex and reported absence of rape and war in our closest living relatives (Bonobos – have they really been observed well enough that we should expect to have seen rape and war?).

The book is highly critical of the Victorian version of marriage, but is somewhat approving of marriage as an institution if it’s more like some non-English cultures where occasional sex outside of the marriage is considered to be fairly harmless.

They also claim there was little violence, because food was abundant and it was normally easier to move to unoccupied land than to fight over resources. They provide decent reasons not to trust arguments that supposedly demonstrate high levels of violence in primitive cultures, but they don’t convince me they’re any more objective than the people they criticize. The most questionable part of this section is their belief that the natural growth rate of pre-agricultural humans was unusually low. They have some plausible reasons for expecting a slower population growth rate than the 25 year doubling time that Malthus expected in the absence of resource constraints, but they don’t come close to providing a good argument that Malthus was off by the factor of 10,000 that would be needed to reconcile the estimated pre-agricultural population growth rates with an absence of resource constraints. I get the impression that they imagine our direct ancestors had no competition from other hominids.

The book’s back flap claims that it contains an explanation of why homosexuality hasn’t been selected out of our genes, but the closest to that I could find in the book was a theory involving bonding which would explain bisexuality but not homosexuality.

Doctors and Smart Drugs

Thursday, December 23rd, 2010

Doctors are more willing to prescribe Viagra than cognitive enhancement drugs.

Why?

The report wonders whether it’s due to conservative tendencies among doctors. But Viagra and Modafinil both became available in the U.S. in 1998. Conservatism doesn’t explain why doctors are slower to accept Modafinil than Viagra. Although maybe combined with more patients asking for Viagra it would be plausible.

Concern over side effects might explain why doctors are less comfortable with Ritalin, but not why three different cognitive enhancing drugs all produced similar comfort levels – about half that of Viagra. And I see no signs that Modafinil is much riskier than Viagra.

Could it be concern that Viagra has an equalizing effect (making people more normal), whereas cognitive enhancers make people who can afford them smarter than the less fortunate? Partly – doctors were more willing to prescribe cognitive enhancers for older patients than younger ones. But the cross-drug comparisons were done for a case where “the patient was a 40-year-old reporting symptoms consistent with the label indications for the respective drug”. I’m pretty sure the label indications describe a patient who is functioning well below normal.

The obvious conclusion part of what’s happening is that doctors believe sex produces larger benefits than cognitive enhancement. If we ignore potentially important externalities such as sexually transmitted diseases versus improved science/technology (would doctors admit to doing that?), I could make a decent case for sex being more valuable. There’s no shortage of evidence that sex makes people happy, whereas there seems to be little or no correlation between cognitive ability and happiness.

(HT YourBrainonDrugs.net).

Counterclockwise

Wednesday, December 15th, 2010

Book review: Counterclockwise: Mindful Health and the Power of Possibility, by Ellen J. Langer.

This book presents ideas about how attitudes and beliefs can alter our health and physical abilities.

The book’s name comes from a 1979 study that the author performed that made nursing home residents act and look younger by putting them in an environment that reminded them of earlier days and by treating them as capable of doing more than most expected they could do.

One odd comment she makes is the there were no known measures of aging other than chronological age at the time of the 1979 study. She goes on to imply that little has changed since then – but it took me little effort to find info about a 1991 book Biomarkers which made a serious attempt at filling this void.

She disputes claims such as those popularized by Atul Gawande that teaching doctors to act more like machines (following checklists) will improve medical practice. She’s concerned that reducing the diversity of medical opinions will reduce our ability to benefit from getting a second opinion that could detect a mistake in the original diagnosis, and cites evidence that North Carolina residents have an unusually high tendency to seek second opinions, and also have signs of better health. But this only tells me that with little use of checklists, getting a second opinion is valuable. That doesn’t say much about whether adopting a culture of using checklists is better than adopting a culture of seeking second opinions. The North Carolina evidence doesn’t suggest a large enough health benefit to provide much competition with the evidence for checklists.

One surprising report is that cultures with positive views of aging seem to produce older people who have better memory than other cultures. It’s not clear what the causal mechanism is, but with the evidence coming from groups as different as mainland Chinese and deaf Americans, it seems likely that the beliefs cause the better memory rather than the better memory causing the beliefs.

Two interesting quotes from the book:

certainty is a cruel mindset

to tell us we’re “terminal” may be a self-fulfilling prophecy. There are no records of how often doctors have been correct or not after making this prediction.

Relational Mobility and Self-Disclosure

Thursday, December 2nd, 2010

Research indicates that cultures in which relationships can be formed and dissolved relatively easily produce more disclosure of intimate information between friends, probably due to a combination of greater need to invest in each relationship and lesser harm from taking risks that alter relationships.

The study compared Japanese culture to U.S. culture, but my impression is that there has also been a significant change over time in the U.S., with internet access increasing relationship mobility, followed by an increase in self-disclosure. (It’s possible that my impression was due to my move from New England to Silicon Valley in 1994 – there’s more social mobility in Silicon Valley, but I didn’t notice much change in self-disclosure until several years later).

It seems likely that the effects of the web on relationship mobility and self-disclosure will grow larger. The trend of increasing mobility has shown few signs of slowing, and the effects on self-disclosure probably lag by at least a few years.