Yesterday, the field of Social Psychology lost a true pioneer. Nalini Ambady, professor of psychology at Stanford, passed away at the far-too-young age of 54 after a long battle with leukemia. She was the first Indian-American woman to teach psychology at Harvard, Tufts, and Stanford, and she is best known for her groundbreaking work on person perception.

Ambady's research, which she conducted along with many illustrious colleagues such as Robert Rosenthal, Nicholas Rule, and Jon Freeman, established that we can form accurate impressions of other people very quickly, even by just viewing "thin slices" of their behavior in as little as 6 seconds. Examples of these "thin slices" include the ability for people to quickly and accurately predict college professor evaluations, sexual orientation, sales effectiveness, power, success, a CEO's company profits, and even political orientation just from looking at pictures of people's faces or viewing incredibly brief video clips.

One thing that I always appreciated about Dr. Ambady's work is that it showed us how much our expectations and first impressions can end up shaping our ultimate realities. For example, take her finding -- in one of her earliest published works, from back in 1993 -- that independent raters could accurately predict how college professors would be evaluated by their students at the end of an entire semester simply by viewing a silent film clip of that professor teaching for less than 30 seconds. It is important to note that she does not say that people can necessarily judge actual teaching effectiveness, or objective teaching ability. Rather, she shows that our snap judgments or evaluations are remarkably resistant to change over time, such that evaluations of a professor, formed by someone who is not even enrolled in that professor's class and who has watched only 30 silent seconds of that professor's nonverbal behavior while teaching, could be indistinguishable from the evaluations that a student would form after taking a class with that professor for an entire semester! Given that we live in a world where perceptions shape reality, this is not a finding to be taken lightly. For example, are politicians truly elected because they are objectively competent, or because people perceive them to be competent? Are teachers given positive evaluations, teaching awards, and raises because they actually teach well, or because their students rate them positively and they are perceived to be good teachers?

Many of the decisions that we make in everyday life have more to do with our perceptions than with objective reality. Ambady not only showed us that these perceptions can be quite accurate, but in my opinion, it's more important that she showed us that we actually form these impressions incredibly quickly - and they are often indistinguishable from the perceptions and judgments that people end up forming when they are given much longer periods of time to do so.

Dr. Ambady's death is a tragedy, and would be thus regardless of the circumstances under which it occurred. But it is especially sad because it could have been prevented. Dr. Ambady's death comes in the wake of a long campaign that had been going on for the past year encouraging people (specifically those of South Asian descent) to sign up for the bone marrow registry in the hopes of finding her a potential match. In the end, 13 potential donors were found -- but half of them were ruled out after further testing, and the remaining half opted not to donate their marrow despite being a match, possibly due to psychological or cultural factors like cultural taboos, doubts and worries, concerns about possible pain or inconvenience, or other possible sources of ambivalence.

In memory of Dr. Ambady, I encourage you to please learn more about the process of bone marrow donation, and consider joining the bone marrow registry, especially if you are non-White (as most non-White racial groups are underrepresented in the donor registry, and it is next to impossible for people to find suitable bone marrow matches outside of their own ethnicities). As noted by colleagues of Dr. Ambady in a statement released earlier today, we can all at least take solace in knowing that Dr. Ambady's campaign to encourage people of South Asian descent to sign up for the bone marrow registry directly resulted in at least 5 other South Asian individuals being successfully matched with donors. If you are reading this, especially if you are of South Asian descent, I hope you consider joining the bone marrow registry. While we all mourn the loss of a great psychological scholar, we can simultaneously hope that this loss might encourage people to take an action that will potentially save future lives.