The UFOs of October:

The Autokinetic Effect and
group dynamics in UFO observations

Michael D. Sofka

This is the outline of a talk presented to The Inquiring Skeptics of Upper New York, February 3, 1999; The Syracuse Technology Club, May 11, 1999; to the Albany Area Amateur Astronomers, November 16, 1999; and, The Central New York Skeptics, September 20, 2006. Slides and notes available in PDF.

Thank you to Taner Edis, Alan French, Eric Krieg, Bob Mulford and Gary Schwartz for their feedback and suggestions.


My talk today is about the perceptual effects that lead many sane, sober people to believe they saw something unusual in the sky. These are the ``lights in the sky'' reports. The sightings which result in calls to the airport or planetarium.

In the interests of full disclosure, I personally don't believe UFOs are alien space craft. But, a lot of people, as many as 11% according to some polls, believe they have seen something unusual in the sky, which they identify as a UFO. If these people are not delusional, or impaired, then what did they see? That is the question I will be answering, at least in part, in this talk. I am specifically going to discuss the autokinetic effect and other illusions of motion that contribute to most, if not all, UFO reports. I'll also be talking briefly about the effects of expectation on perception and recall. The message to take home is that ordinary people can see something unfamiliar in the sky, and interpret it in ways consistent with what they expect of UFOs, even though in reality they saw nothing unusual or abnormal.

I won't be talking about Alien Abductions, Fox Autopsy films, Crashed Flying Saucers, Cattle Mutilations, UFO cults or any of the more exotic UFO-related claims. I also won't be talking about hoaxes, although there have been some famous UFO hoaxes. And, I won't be covering the history of UFOs, even though I find that topic to be fascinating in its own way.

Any of these other topics could be the source of many other talks. But, I'm going to stick to your basic bread and butter ``lights in the sky,'' which still make up the majority of UFO reports, and are the foundation of the pyramid of UFO claims. That is, if there were no underlying real phenomena---the illusions of motion---there would be many fewer reports of ``lights in the sky,'' and they would not have the same degree of credibility. Without that base, hoaxed UFO photos, and claims about finding a landing site, or talking with occupants would be less believable.

To tie the talk to a particular, ``real,'' event, let me read to you from an October, 1994 Albany Times Union article entitled: ``Twinkle twinkle little starmen?''

And, the report goes on to elaborate that there were up to a dozen saucer shaped objects the size of a dime held at arms length. Think about that for a minute, 12 objects the size of a dime held at arms length. How big is that? If you held a dime at arms length, how would it compare in size to the full moon?

Two television news stations even showed up, and filmed the object---the film crew saw only one---the next day, which provided an inadvertent, but very important, clue.

Skeptics and UFOs (Disclaimer I).

Before discussing the UFOs of October, a little background is in order: background on illusions of motion, on group dynamics and, most importantly background on Skeptics.

  • Skeptics attempt to apply science and rational methods to claims of the paranormal and fringe science. They work within established scientific framework, although some creativity may be necessary to apply science to such bizarre areas as UFOs, bigfoot sightings, and so on.

  • I contrast this ``scientific skepticism'' with ``philosophical skepticism,'' which takes more of a doubting Thomas approach to claims. The philosophical skeptic is likely to doubt anything they don't see themselves, or at least strive for complete consistency in all aspects of belief. I'm more concerned with what science can tell us, and leave the non-scientific alone.

  • For example, since it is believed likely that there are some extraterrestrial intelligences, and since they may exceed our technology by millions (even billions) of years, we cannot dismiss out of hand the claim that some UFOs are of extraterrestrial origin.1 But:

  • I want to emphasize: it cannot be claimed with 100% certainty that the effects I'll be talking about are the explanation for any particular event. But: With those preliminaries out of the way, lets get to some science.

    What is the Autokinetic Effect?

    I've already mentioned the autokinetic effect, and it is in the title of the talk. What is the autokinetic effect?

  • The Autokinetic effect is a perceptual illusion in which motion is perceived in an object that is really stationary. It is an illusion of motion---and a very common one.

  • It is most often perceived when a small bright object is seen against a dark background, such as a keyhole in a dark room3, or a bright star against the evening sky.4

  • It is caused by small eye-movements. Our eyes are constantly moving, the brain compensates for this movement to create a stable image. When compensating, the brain is using prior knowledge of background---that is, knowledge of what does and does not move.

  • Against an ``impoverished'' background, however, the brain mistakes the eye's movement for object movement. Once your brain has made the ``decision'' that the object is moving, the effect is persistent and very realistic.

  • The autokinetic effect is robust:

  • A good time to see it is right now [January 1999] in the early evening:

  • Once the illusion of motion has set in, it is difficult to ignore; even if you know the object is stationary, it appears to move.

  • To those who do not know what is happening, it is very difficult to convince them their eye, and not the object is moving.

    Muzafer Sherif's study.

    The autokinetic effect is also subject to suggestion. That is, you can suggest to people what ``motion'' the light is making. Multiple people can also make suggestions to each other about what they see without realizing what they are doing. When this happens, the autokinetic effect becomes an unintentional Ouija board.

  • In 1931, Muzafer Sherif, a social psychologist, used the autokinetic effect to study the formation of group norms.5 Group norms are accepted beliefs or behaviors in a group of people. For example, how close should you stand to another person during a face-to-face conversation.6

  • In Sherif's study:

  • Sherif's results are also robust, and have been replicated in hundreds of subsequent studies of group dynamics. It turns out to be trivially easy to influence what movement the light is reported to take, and groups of subjects always come to some agreement on what they are seeing. For example:

    Other Perceptual Effects.

    The autokinetic effect is not the only illusion of motion that has a role in UFO reports. For example, there is also:

  • Autostatic Effect: Similar to the autokinetic effect, the autostatic effect is when a moving object appears stationary. This can happen, for example, when watching a satellite traverse the sky. Many people do not realize that you can see satellites with the naked eye, and they are another suspected source of UFOs---one which is difficult to track down since orbital data for satellites can be difficult to come by (some is classified). [This is changing, however, as more programs for calculating orbits based on observation become available via the Internet. There are also active satellite watchers, and web sites with links to orbital information. See and --mds 29 September 1999, thanks to Allen Thompson for bringing these web sites to my attention.]

  • Stroboscopic Effect: lights blinking in sequence create an illusion of motion---for example, stars being seen through wispy clouds.

  • Induced movement: An object may be perceived to move when it is the background that is really moving. We are all familiar with this from sitting in a car, and jamming on the brakes in panic when we think the car is moving backwards, only to discover that it was the car in front moving forward. This also happens when we watch the moon or a star ``racing'' through clouds on a windy night.

  • Moon or star chasing: The moon and stars are so distant, that they do not change position against the background when we move. This creates the illusion that they are following us. If that is combined with some other event, such as a fireball, or if it occurs when a person is nervous or tired, a UFO encounter may be in the making.

  • Brightness/Size/Distance constancy: In the absence of other cues a brighter object is perceived as being larger and closer than a dimmer object. In the case of stars, they are all the same size to the naked eye---they are all point sources. Yet, the brighter stars are perceived and remembered as being ``bigger.'' (An amateur astronomer friend remarked that people will ask him about the star that was ``as big as a house.'')

  • Atmospheric shimmering: can make a steady object appear unsteady, and can cause a prismatic effect so that a white object may appear to change colors. This often creates an illusion of rotation, as colors shift (similar to the stroboscopic effect).

    It should be noted that training does not make these effects go away. At most, training can alert people to when they may experience an illusion of motion or perception, and take action (such as viewing the ``UFO'' through tree limbs) to eliminate or adjust for it. Or, when they should temper or compensate their answers for such effects.

    It should be specifically noted that pilots and military personnel do not get special training in how to ignore optical illusions, or how to observe the night sky. Quite the contrary, more advanced pilot training includes ignoring sensory feelings and believing instruments. Our senses can lie, we must trust our instruments. As such, reports of UFOs by pilots are as accurate or inaccurate as those of non-pilots under the same conditions.


  • Memory of a UFO observation are also influenced by recall effects. What a person recalls seeing is influenced by what they believe they have seen---especially in an ambiguous and emotionally charged event such as a crime, or observing a UFO.

  • Elizabeth Loftus and her students:8

    It is important to keep in mind that:

  • Most UFO observations are not due to a single effect, and instead involve a collection of perceptual illusions which our brains tie together into a narrative consistent with what we believe we saw.

  • A sighting may start by looking at a very bright ``star,'' and through a combination of perceptual illusions and leading questions (from other group members, or from investigators) ends with reports of dime sized saucers. It is important to remember that both perception and recall are active events influenced by what we believe we are/were looking at.

    The Autokinetic Effect in Practice.

    Ok, we know the autokinetic effect, and other illusions of motion, exist. And, we know that group dynamics can greatly influence the illusion, and the consistency of their reports. What evidence is there that this has ever happened with ``real'' UFOs?

  • The Exeter, New Hampshire UFOs.

  • The Mexico City UFOs.

  • The 1993 Perseid Meteor Shower, Bartlett, New Hampshire.

    This final story is one of a personal nature.

    There was a fair sized crowd observing at that time, many were looking at us, and at Vega. They looked back and forth---I looked at them, and my father, and they looked back. The temptation was very strong to say: ``you're right, it's moving to the left---look at it!'' (all in the interest of Science, you understand). Never before was I so upset about being an ethical skeptic.

    The autokinetic illusion, once it starts, is very strong. Knowing the object isn't moving, doesn't make it go away.

    The UFOs of October.

    I started off by reading from the Albany Times Union, about UFOs seen over Stillwater NY. I hope by now you have a better understanding of the kinds of effects that may have lead to those reports.

  • What other evidence is there that the Stillwater UFO was a bright planet or star?

  • A year later, I saw Ray Cecot give a presentation at a local MUFON gathering:

    Call me skeptical, even cynical, but at 11 pm the eyewitnesses to the Stillwater UFOs demonstrated in no uncertain terms that they could not tell the difference between an interstellar spacecraft, and a bright star. Why should I believe they had that ability at 8 pm?

  • What about the ``dime sized objects?'' How do we go from stars, to a dozen dimes? It is important to note that people are very poor at judging size and distance without good visual cues:

    I had asked you earlier how you thought a dime measured against the size of the full moon. If you held a dime at arms length, how big would it appear if held up against the moon? Think about this again, before reading further.

    Summary and Conclusions (Disclaimer II).

    I started this talk with a disclaimer and I will end with a disclaimer.

    The truth be told, neither I nor anybody else knows what the unnamed women, her daughter and seven neighbors saw at 8 pm from Stillwater NY. It could have been a distant jet, a bright star seen through clear, cooling skies (the observing conditions at the time). The star or planet could have been augmented by the autokinetic effect (as seemed evident from the network news report), or some combination of these and other factors.

    And who knows, it could have been an interstellar craft. The evidence, however, hardly supports such an extraordinary hypothesis---especially when simple, alternative explanations, employing well-understood phenomena, are available.

    The Stillwater event, however, when combined with the media coverage, spun off its own mini-wave of UFO reports. It was not as big or dramatic as the current Mexican wave, to be sure. But like the Mexican wave, the stories have became more elaborate with time. Attendance at student sponsored UFO symposium at Rensselaer Polytechnic Institute was high. (Although, it is interesting to note, very few of the attendees were students.) And, this included the usual collection of drawings of UFOs, pictures of crop circles, support groups for abduction victims, etc.

    Most of these people, no doubt, were already believers and all the local flap did was give them a booster shot. However, many people within the WRGB and WTEN listening areas now know that something, maybe an alien spacecraft, was seen in Stillwater, since no additional followup was offered in newspapers or on TV. The evidence, however, simply doesn't support this claim.

    Instead, the evidence is consistent with misperception of celestial objects, augmented by the autokinetic effect and possibly other illusions of motion and recall. It is possible for ordinary people to see something unfamiliar, and even exciting and extraordinary, in the night sky. That doesn't mean what they saw is inexplicable, or even unusual. On the contrary, it may be the familiar night sky, viewed by people not so familiar with it, augmented by some popular images of flying saucers and aliens.

    1 E.g., the Fermi paradox. That is, a civilization that advanced should have contacted us by now. For a good review of the Fermi paradox see Zuckerman, B. and Hart, M.H., Extraterrestrials: Where are They?, Second edition, Cambridge University Press, 1982/1985, and Dick, S.J., The Biological Universe: The Twentieth-Century Extraterrestrial Life Debate and the Limits of Science, Cambridge University Press, 1996.

    2 Which damages credibly, IMHO

    3 Hence, it is also called the ``keyhole'' illusion.

    4 Goldstein, E.B., Sensation and Perception, Wadsworth Publishing Company, 1980, pp. 265--266 (or any introductory perception book), George, L., Alternate Realities: The Paranormal, The Mystic and the Transcendent in Human Experience, Facts On File, 1995, p. 27.

    5 (Sherif, M., A study of some social factors in perception, Archives of Psychology, 27, pp. 311--328, 1935). Sherif, M., An experimental approach to the study of attitudes, Sociometry, 1, 1937, pp. 90-98.

    6 Sherif was Turkish, and he noticed people kept moving away from him as he talked.

    7 A thorough summary of the autokinetic literature in social psychology can be found in Carolyn Wood Sherif, Orientation in Social Psychology, Harper & Row, New York, 1976. George, Alternate Realities, contains entries for autokinetic effect, and for group dynamics of unusual experiences.

    8 Elizabeth Loftus' early work on memory and recall is summarized in: Loftus, E.F., Eyewitness Testimony, Harvard University Press, 1979. Information about reconstructive recall in a variety of natural settings is in Neisser, U., Memory Observed: Remembering in Natural Context, W.H. Freeman and Company, 1892.

    9 Fuller, J.G., Incident at Exeter, Putnam, 1966; paperback, Berkeley, 1974.

    10 Sheaffer, R.. The UFO Verdict: Examining The Evidence, Prometheus, 1986, pp. 111--119. The fit was not statistically significant, nor could it be with such a small sample size. Sheaffer discusses other evidence that the Exeter UFOs were celestial bodies, such as a correlation with cloud cover, regular nightly appearances that shift according to sidereal time, and descriptions of the object consistent with celestial bodies known to be visible at that time.

    It is interesting to note that in the definitive work supporting one of the best documented UFO cases, only 7 observations out of nearly 100 occurring over 5 months were written up with enough accuracy to tell both approximate direction and date of observation.

    11 Elders, Lee., and Jaime Maussan, Messengers of Destiny, Genesis III Productions, narrated by Brit and Lee Elders.

    12 French, A. The Why-Files, December 1994.