We have all been talking about this to death, but I figured I would add my two cents. Ben Barres wrote an editorial in the most recent issue of Nature about the issue of gender disparity in science. He mentions the comments of Larry Summers among others things and that he felt that those comments were out of line.

What happens at Harvard and other universities serves as a model for many other institutions, so it would be good to get it right. To anyone who is upset at the thought that free speech is not fully protected on university campuses, I would like to ask, as did third-year Harvard Law student Tammy Pettinato: what is the difference between a faculty member calling their African-American students lazy and one pronouncing that women are innately inferior? Some have suggested that those who are angry at Larry Summers' comments should simply fight words with more words (hence this essay). In my view, when faculty tell their students that they are innately inferior based on race, religion, gender or sexual orientation, they are crossing a line that should not be crossed -- the line that divides free speech from verbal violence -- and it should not be tolerated at Harvard or anywhere else. In a culture where women's abilities are not respected, women cannot effectively learn, advance, lead or participate in society in a fulfilling way.

There are couple of things that I should say. First, I have tremendous respect for Ben Barres as a person, as a male, and as a scientist. (Yes, I know that he recieved a sex change. I meant everyone of those groups.) While I was an undergraduate at Stanford, I had the considerable pleasure of taking a course in neurology organized by him. He also has been at the forefront of the fight to convince people that oligodendrocytes are not simple structural cells, a point of view for which -- considering I study them as well -- I have considerable sympathy.

I also agree with 95% of what he said in his editorial. Basically, his core argument was that there is no compelling evidence that women cannot be successful at science, but there are still large disparities that suggest entrenched discriminatory practices. I agree completely. I have not aware of a single cognitive trait for which men and women differ in a meaningful way. By meaningful, I mean a trait for which the variability between all people does not completely dwarf the differences in averages between the sexes. Furthermore, differences in cognitive traits do not suggest differences in capacity; they may simply suggest differences in cognitive style.

What concerns me and what has got me thinking is his comment about the bounds of debate. Barres considers the comments of Larry Summers -- in which he said that some of gender disparity in science might be related to intrinsic differences between the sexes -- is outside the realm of acceptable scientific debate. It is not that I have a problem with that -- I agree -- but I am trying to think about what reasonable standard one could use for know what is in and what is out of the realm of debate. While I think he is incorrect, it is unfair to criticize Mr. Summers for his comments if we cannot collectively agree on what we consider acceptable -- otherwise how is one to know whether one is crossing the line.

I can think of two factors that relate to whether a statement -- a hypothesis, a scientific idea, etc. -- is acceptable or whether it crosses an unacceptable ethical line.

• Evidence -- A statement must possess a reasonable amount of evidence collected in good faith.
• Possibility of Misuse -- A statement must be made with an awareness for the capacity of such statements to harm.

I see these two factors acting in opposition to one another. Brash statements can be made and can be made acceptably in a debate, but only insofar as the statement cannot harm others. The more harmful a statement is the more evidence it requires to make it.

Viewed in this way, the problem with Larry Summers statements is not that he said something offensive and possibly harmful to women. The problem is that he based his statement on evidence that was not substantial.

I guess I stand by the premise that any statement is an acceptable on in a scientific debate, but scientists do have to be aware about the consequences of such statements -- and how they are sometimes misused by nonscientists -- in the way that they make them.

Anyway, I am curious to hear whether people think these criterion are reasonable. I have been thinking about this a lot, and I really don't think it is fair to be angry with Larry Summers unless in the future we can develop a common standard for this sort of thing.