Deriving Intent From Biometrics
Biometrics as a measure of intent dates at least to the polygraph. Humans often do have physical reactions to stress, but does this kind of system employed as a filter for further screening really buy us much safety?
In the name of finding terrorists before they board an airplane, the TSA has adopted a number of “advanced” personal profiling methods: essentially, agents looking for tells, signs of nervousness, or other vague symptoms that may or may not be harbingers of doom.
There are of course many innocent explanations for a nervous manner, sweaty shirt or face, irritated look, twitchy fingers, etc. They include people just having had arguments with their friend or spouse, hurrying to catch a flight, getting caught in traffic on the way to the airport, being recently fired, being nervous about a first flight, having a sweating problem by nature, or hurriedly typing an emotional blog entry or Facebook post into their cell phone.
The TSA apparently believes so much in this approach that they want to scale it up. And the only way to do that is to make a computer do the scanning for you. CNN had this article on October 6th: “Will Airports Screen for Body Signals? Researchers Hope So.”
I like the title, because it’s likely that only the researchers getting paid to conduct this work are hopeful that it will get adopted. There is a really nice quote from the article:
“I haven’t seen any research that shows that those measures from the autonomic nervous system … measuring blood pressure, measuring breathing, measuring heat on the face, are at all related to intent,” said Stephen Fienberg, professor of statistics and social sciences at Carnegie Mellon University.
Spot on! Identity doesn’t measure intent, and neither does your biometrics, if just for the plain fact that your individual heat signature, heart rate, etc. are exactly that: an individual signature about which the population statistics have nothing to say and no predictive power. Forensic psychology researchers involved in creating risk assessment measures (e.g., for criminal recidivism rates) argue about whether such measures can actually predict an individual’s behavior, since the rates of a population don’t determine what an individual released on parole and able to exercise free will (and subject to both the social support and temptations of the outside world) might actually do. For example, measures like the HCR-20 are instruments for assessing the risk of violence, but mainly with in the context of ongoing psychotherapy sessions in a doctor-patient relationship.
Now, as a researcher who routinely solicits money from Federal agencies to support my work, I understand that the scientists involved in trying to create this technology will have some reasonable claims about its limitations and shortcomings. They’ll have a justification for why it will work well, and they may even had made a few fundamental breakthroughs in terms of gathering data from dark or dimly lit faces, bad angles, and the like. Unfortunately, they are also likely to have adopted the beliefs of their funding agency: that this type of profiling works to pick out those engaged in illegal activities or those intent on causing harm to air or rail passengers.
I’d like to see this system made to work from high up above Grand Central Station’s main floor, or in a high school auditorium, a supermarket, a sports venue, or a crowded student center. These are dynamic, real environments, not controlled lab conditions where the subject peers directly into the camera in good lighting.
All that aside, however, this view stunned me:
Civil liberties groups maintain this screening technology is an invasion of privacy. “Nobody has the right to look at my intimate bodily functions, my breathing, my perspiration rate, my heart rate, from afar,” said Joe Stanley of the ACLU.
…
[Project manager Robert] Burns denied the project is a violation of privacy. “We’re looking at signals you give off naturally. We’re not asking for any personal information. We’re not asking anything about you,” he said.
Burns is entirely correct — they are not asking anything about you: they are taking it forcefully from under your nose without permission. Earlier in the article, Burns states that “We’re looking for those signals that your body gives off naturally.” The problem is that technology is allowing government workers to do something that they didn’t have the power to do before. These properties are subtle and not detectable by the human eye when scanning a large crowd: heart rate, body temperature, perspiration under clothing, eye movement, etc.
Although your body does display these properties, it does not advertise them on a billboard: there is no neon sign with your heart rate plastered to your forehead. Why should government agents have the power to effectively augment their five senses to know your physical condition perhaps more intimately than you know it yourself?
