The chain email heuristic says that if an “informative” chain email lands in your inbox it should be considered completely false until the information is corroborated. For some reason, otherwise intelligent people exhibit gross credulity when faced with (often obviously) fictitious or improbable claims in forwarded email messages. My hunch is that since the messages are most often forwarded by friends and coworkers, people who the recipient trusts, the recipient uses the friend’s judgment in proxy, or the assumption that the friend used judgment, and thus makes himself ready to believe the tripe in front of him.

Prime examples include:
  1. Things you didn’t know your cellphone could do (example)
  2. Rapist interview and rape safety information (example)
  3. Carjacking using a piece of paper (example)

Let’s go through them one at a time.

Things you didn’t know your cellphone could do

The CEO at a former employer actually forwarded this email firm wide (he wasn’t the most technically savvy fellow). One of the “cool things” that your cell phone can do is allow you to unlock your car from a great distance. The scenarios is that you’ve locked your keys in your car or you’ve lost them, and you have someone else find your extra set of keys and call you while you’re by your car. The second person places the lock transponder by their phone and presses the “unlock” button and you put your cellphone close to your car and MAGIC! your car unlocks.

The email always recommends the use of a cellphone on both ends, as if the transmitting cellphone - as a radio device - can somehow pick up and relay the transponder signal. The transponder works with electromagnetic waves, mind you, not sound. However the receiving phone doesn’t “know” what kind of device its talking to. The device’s native environment is “encapsulated” in object oriented design-speak. The only thing transmitted between the two devices in this case, via the network of radio towers and telecom cables, is the encoded audio. The transmitting phone would have to interpret the transponder signal, communicate it through the phone network, and then the receiving phone would have to be able to interpret the signal and somehow be able to and know to transmit the transponder’s radio signal. This suggestion takes the gold medal in the Special Olympics of email forwards. The rest of the email is dubious, too.

Rapist interview and rape safety information

I’ve seen various incarnations of this email, or at least bits and pieces in different emails. It starts off in the main case in the passive voice (no subject makes it easier to be vague) and mentions that a group of “rapists and date rapists in prison” were interviewed about what they look for in a potential victim. No mention of the heterogeneity of this group. Rapes, like murders, are perpetrated for various reasons. If the same question were asked of murderers it would sound ludicrous, as if some predictable line might be drawn through the motivations of a spurned lover and a serial killer. Also, if this was a serious interview who did it? When was it done? Where was the data published? The lack of citation is a key signal that you’re dealing with phony information.

The self defense information that follows is more paranoia that preparation, and has been pretty thoroughly gutted by [women’s] self defense experts.

Carjacking using a piece of paper

This email starts off warning the reader about a spate of recent carjackings in their area. The carjackings are perpetrated when the victim enters his car in a parking lot or garage. There will be a piece of paper on the rear windshield. The victim then gets out of the car to remove the piece of paper obstructing his view. When he gets around to the back of the car a carjacker - hiding in the shadows (under the car?) - attacks the victim’s lower extremities and steals the car.

The first signal that this is likely false is the claim that this is new crime wave in the reader’s area. In an example of the efficient markets hypothesis at work outside of economics, why wouldn’t the reader have heard about this crime in the local news? The local news never misses a chance to report on lurid new crimes. The second signal that this is likely false is the absurdity of the entire chain of events. How well can the attacker really hide? Would the attacker hide under the car, thus putting himself at risk of getting run over? If you wanted to steal someone’s car in a parking lot, would this make sense as a strategy to you? Probably not.

We hear new claims every day and more often than not lack the time and the expertise to verify each of them. Thus we rely on proxy filters such as trust in friends or authority. The trust should end at email forwards, and as a quick validity check readers should look for signals that the claims are reliable.