Freethought & Rationalism Archive

Vorkosigan · 06-05-2002, 07:02 AM

Here's what Hess says:

"Our study suffers from four principle limitations. First, several of our results have
alternative interpretations (e.g., perhaps people with friends are more likeable, and
therefore subjects were less inclined to informationally aggress against them). Second,
almost all of our subjects were college students between the ages of 18 and 22; our results
may not generalize to other demographic segments of the population. Third, our studies
and the many supporting studies that we cite were conducted in the US, and may not be
cross-culturally valid. We are proposing the people posses a set of innate psychological
mechanisms to collect, evaluate, and disseminate gossip. Innate psychological
mechanisms must be universal, so our proposal requires considerable cross-cultural
validation."

I think the future Dr. Hess is well aware of the cross-cultural limitations.

Vorkosigan

Dr Rick · 06-05-2002, 07:22 AM

Quote:

Originally posted by Vorkosigan:
Why don't you take a look and see what you think?

I think I made an ass of myself; I should have known better than to criticize a paper on the basis of a news report.

Ms. Hess's work is scholarly and compelling; she acknowledges alternative explanations for her observations and provides data from human behavioral studies (as opposed to animal studies)to support her interpretation.

Thanks to Michael for providing the link.

For those who don't want to read some 40 pages (though it is worthwhile), Ms. Hess's <a href="http://www.uweb.ucsb.edu/~hess/meangenes.html" target="_blank">Review of Mean Genes</a> provides an excellent summary of what EP is and is not meant to be:

Quote:

Evolutionary psychologists look at adaptations, not genes, and there is an excellent reason for this. As critics of sociobiology never tire of pointing out, we understand very little about the relationship between genes and behavior. This would seem to cut evolutionary psychology off at the knees. The key insight, however, is that one infers adaptation not from genes but from evidence of design. We know without doubt that the uterus is an adaptation not because we know which genes build uteruses (we don't), but because the features of the uterus show overwhelming evidence that they have been designed to solve the critical reproductive problem of containing the developing embryo for nine months, and then expelling it at birth.

In the hands of someone like Hess, the field of EP holds promise.

I stand corrected and slightly more educated.

Rick

[ June 05, 2002: Message edited by: rbochnermd ]

joshack · 06-05-2002, 09:31 AM

Rick,

I'm confused as to where you get your information regarding EP. Articles testing claims founded upon evolutionary assumptions are published all the time, in the largest of psychology journals (thereby meeting the standards of any psychological study). The question is not whether we can absolutely prove whether evolution has indeed led to the behaviors observed. The question is - can we use evolutionary ideas to generate hypotheses that cannot be explained by other theories. The answer to this question is a resounding yes.

Free-form speculation (common to many popular press books) is not the place to look if you are truly interested in how evolutionary behavior theories are tested.

scigirl · 06-05-2002, 09:57 AM

Hey everyone,

I just thought I would mention - I am very interested in this thread, and I am pleased that people here who are highly educated and have differing opinions have remained civil and admitted errors. I think this topic tends to get us riled up a bit, and I'm glad to see that we scientists can use our differing opinions and backgrounds (from basic scientists to MDs etc) to learn from each other. Woo Hoo!

I plan on reading up more about these links, since evolution of humans and human behaviors is very interesting to me. Thanks for this thread, it is very refreshing after reading the one now infested with randman.

<img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

scigirl

brighid · 06-05-2002, 10:00 AM

Quote:

Obviously rape is dangerous for the scrawny male because if he gets caught by the powerful male he is going to be a pile of lean meat and bones. Female selection may produce the large males yet the skinny nasty males may be perpetuated by their ability to rape. Females would not be best served by mating with the scrawny males but the genes in those males don't care what the female position is,(so to speak).

Just as with the human male (not all of course

) ... hence the reason for birth control and abortion so we don't have to give birth to children fathered by men against our will.

B

Dr Rick · 06-05-2002, 10:05 AM

Quote:

Originally posted by joshack:
Rick, I'm confused as to where you get your information regarding EP.

In all the wrong places, apparently, but that has now changed.

Rick

Dr Rick · 06-05-2002, 10:10 AM

Quote:

Originally posted by brighid:
...hence the reason for birth control and abortion so we don't have to give birth to children fathered by men against our will.

But let's not get too carried away, brighid; it might be a bit of a stretch at this juncture to attribute pharmacological hormonal manipulations and surgical techniques to evolutionary adaptions.

[ June 05, 2002: Message edited by: rbochnermd ]

The Lone Ranger · 06-05-2002, 10:24 PM

Quote:

Originally posted by rbochnermd:

If you do know, could you tell me where this study was published?

There have been several different "t-shirt" studies published, most famously by C. Wedekind and his colleagues. A few examples follow:

Wedekind, C., T. Seebeck, F. Bettens, and A. Paepke. 1995. MHC-dependent mate preferences in humans. Proceedings of the Royal Society of London B, Biological Sciences 260:245 � 249.

Here's the abstract:

Quote:

One substantial benefit of sexual reproduction could be that it allows animals (including humans) to react rapidly to a continuously changing environmental selection pressure such as coevolving parasites. This counteraction would be most efficient if the females were able to provide their progeny with certain allele combinations for loci which may be crucial in the parasite-host arms race, for example the MHC (major histocompatibility complex). Here we show that the MHC influences both body odours and body odour preferences in humans, and that the women's preferences depend on their hormonal status. Female and male students were typed for their HLA-A, -B and -DR. Each male student wore a T-shirt for two consecutive nights. The next day, each female student was asked to rate the odours of six T-shirts. They scored male body odours as more pleasant when they differed from the men in their MHC than when they were more similar. This difference in odour assessment was reversed when the women rating the odours were taking oral contraceptives. Furthermore, the odours of MHC-dissimilar men remind the test women more often of their own actual or former mates than do the odours of MHC-similar men. This suggests that the MHC or linked genes influence human mate choice today.

The entire article is available online from JSTOR <a href="http://www.jstor.org/view/09628452/ap000060/00a00030/0" target="_blank">here.</a>

Wedekind, C., and S. Furi. 1997. Body odour preferences in men and women: do they aim for specific MHC combinations or simply heterozygosity? Proceedings of the Royal Society of London B, Biological Sciences 264: 1471 � 1479.

Again, here's the abstract:

Quote:

The major histocompatibility complex (MHC) is an immunologically important group of genes that appears to be under natural as well as sexual selection. Several hypotheses suggest that certain MHC-allele combinations (usually heterozygous ones) are superior under selective pressure by pathogens. This could influence mate choice in a way that preferences function to create MHC-heterozygous offspring, or that they function to create specific allele combinations that are beneficial under the current environmental conditions through their complementary or epistatic effects. To test these hypotheses, we asked 121 men and women to score the odours of six T-shirts, worn by two women and four men. Their scorings of pleasantness correlated negatively with the degree of MHC similarity between smeller and T-shirt-wearer in men and women who were not using the contraceptive pill (but not in Pill-users). Depending on the T-shirt-wearer, the amount of variance in the scorings of odour pleasantness that was explained by the degree of MHC similarity (r^2 ) varied between nearly 0 and 23effect of gender in this correlation: the highest r^2 was actually reached with one of the male odours sniffed by male smellers. Men and women who were reminded of their own mate/ex-mate when sniffing a T-shirt had significantly fewer MHC-alleles in common with this T-shirt-wearer than expected by chance. This suggests that the MHC or linked genes influence human mate choice. We found no significant effect when we tested for an influence of the MHC on odour preferences after the degree of similarity between T-shirt-wearer and smeller was statistically controlled for. This suggests that in our study populations the MHC influences body odour preferences mainly, if not exclusively, by the degree of similarity or dissimilarity. The observed preferences would increase heterozygosity in the progeny. They do not seem to aim for more specific MHC combinations.

The article is available online from JSTOR <a href="http://www.jstor.org/view/09628452/ap000106/00a00100/0" target="_blank">here.</a>

Of course, nothing is ever completely clear-cut. In 1997, C. Ober et alia conducted a study of the Hutterites. By comparing the MHCs of husbands and wives, they concluded that the Hutterites were (presumably unconsciously) mating dissortively -- that is, choosing mates with dissimilar MHCs.

On the other hand, P. W. Hedrick and F. L. Black in 1997, and Y. Ihara et alia in 1999 failed to find evidence for dissortive mating for MHCs in South American Indians and Japanese, respectively.

***

Penn, D. J., and W. K. Potts. 1999. The Evolution of Mating Preferences and Major Histocompatibility Complex Genes. The American Naturalist 153(2): 145 � 164.

This paper provides interesting commentary on studies of assortive mating practices in various mammal species, including humans. It also includes comments on the Wedekind studies. It is available online as a PDF file <a href="http://stormy.biology.utah.edu/publications/amnat.pdf" target="_blank">here.</a>

I'll leave off with this article, just because I though it rather interesting:

Jacob, S., M. K. McClintock, B. Zelano, and C. Ober. 2002. Paternally Inherited HLA Alleles are Associated with Women�s Choice of Male Odor. Nature Genetics 30:175-179.

The abstract:

Quote:

The major histocompatibility complex (MHC) is a source of unique individual odors that influence individual recognition, mating preferences, nesting behavior and selective block of pregnancy in animals. Such phenomena have been difficult to study in humans, because the human leukocyte antigen (HLA, human MHC) loci are the most polymorphic loci in the human genome, with the potential to generate millions of unique combinations of genotypes. In addition, high variability in background odors, encoded by the rest of the genome and influenced by cultural practices, contribute to a low signal-to-noise ratio that could mask HLA-based olfactory cues. Here we show that women can detect differences of one HLA allele among male odor donors with different MHC genotypes. Notably, the mechanism for a woman's ability to discriminate and choose odors is based on HLA alleles inherited from her father but not her mother. The parents' HLA alleles that she does not inherit show no relationship with odor choice, despite exposure to these HLA-encoded odors throughout her life. Our data indicate that paternally inherited HLA-associated odors influence odor preference and may serve as social cues.

It is available online as a PDF file <a href="http://www.nature.com/cgi-taf/DynaPage.taf?file=/ng/journal/v30/n2/full/ng830.html&filetype=pdf" target="_blank">here.</a>

'Night all,

Michael

{Edited to get the links to work.}

[ June 05, 2002: Message edited by: The Lone Ranger ]

Dr Rick · 06-06-2002, 01:01 PM

Thanks, Michael.

I couldn't access JSTOR articles but am printing-out the two pdfs as I post; I'll read them on the plane this weekend.

Rick

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06-05-2002, 07:02 AM	#31
Vorkosigan Contributor Join Date: Jan 2001 Location: Barrayar Posts: 11,866	Here's what Hess says: "Our study suffers from four principle limitations. First, several of our results have alternative interpretations (e.g., perhaps people with friends are more likeable, and therefore subjects were less inclined to informationally aggress against them). Second, almost all of our subjects were college students between the ages of 18 and 22; our results may not generalize to other demographic segments of the population. Third, our studies and the many supporting studies that we cite were conducted in the US, and may not be cross-culturally valid. We are proposing the people posses a set of innate psychological mechanisms to collect, evaluate, and disseminate gossip. Innate psychological mechanisms must be universal, so our proposal requires considerable cross-cultural validation." I think the future Dr. Hess is well aware of the cross-cultural limitations. Vorkosigan

06-05-2002, 09:31 AM	#33
joshack Junior Member Join Date: May 2002 Location: valley of the hell, AZ Posts: 26	Rick, I'm confused as to where you get your information regarding EP. Articles testing claims founded upon evolutionary assumptions are published all the time, in the largest of psychology journals (thereby meeting the standards of any psychological study). The question is not whether we can absolutely prove whether evolution has indeed led to the behaviors observed. The question is - can we use evolutionary ideas to generate hypotheses that cannot be explained by other theories. The answer to this question is a resounding yes. Free-form speculation (common to many popular press books) is not the place to look if you are truly interested in how evolutionary behavior theories are tested.

06-05-2002, 09:57 AM	#34
scigirl Veteran Member Join Date: Jul 2001 Location: Seattle Posts: 4,261	Hey everyone, I just thought I would mention - I am very interested in this thread, and I am pleased that people here who are highly educated and have differing opinions have remained civil and admitted errors. I think this topic tends to get us riled up a bit, and I'm glad to see that we scientists can use our differing opinions and backgrounds (from basic scientists to MDs etc) to learn from each other. Woo Hoo! I plan on reading up more about these links, since evolution of humans and human behaviors is very interesting to me. Thanks for this thread, it is very refreshing after reading the one now infested with randman. <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" /> scigirl

06-06-2002, 01:01 PM	#39
Dr Rick Veteran Member Join Date: Jul 2000 Location: USA Posts: 5,393	Thanks, Michael. I couldn't access JSTOR articles but am printing-out the two pdfs as I post; I'll read them on the plane this weekend. Rick

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