The Beck effect is difficult to replicate online, because it involves testing reaction times. However, I think I’ve figured out a way to approximate the effect. This movie (Quicktime required) will show you how it works. Just follow the directions on the opening screen:
Now, which letter did you see first? Let’s make this a poll:
If we manage to replicate the effect, there should be a bias in the results, which I’ll explain below so everyone has a chance to try it out before learning the “answer.”
In the 1960s, Jacob Beck found that when searching arrays of letters like this, viewers were faster to find the Ts tilted on their side than the standard Ls. Yet when asked simply to identify a sideways T or upright L by itself, viewers are equally fast for each letter. If we’ve successfully replicated it, more people should answer “T” than “L.”
Interestingly, David Navon and Ruth Kimchi have found that the effect persists even when just two objects are being compared: We identify a sideways T next to an upright T faster than an L next to an upright T.
So what about identifying the T or L in when accompanied by upright Ts is different from identifying them alone? A couple of explanations have been proposed.
One explanation posits that when we’re looking at a field of Ts, we’re more attentive to similar shapes, so we notice the tilted Ts more rapidly. Another explanation argues that sideways Ts are actually less similar to upright Ts: since the Ls “blend in” we take longer to locate them.
Navon and Kimchi noted that both of these explanations rely on the specific shape of the letters. What if they could replicate the Beck effect without relying on shapes at all? In a 2004 study, they did just that. Instead of letters, they used colors. Viewers were shown four patches of color; three were always dark green, while the fourth could be either light green, dark green, or brown. They were told to press a corresponding button indicating which color the fourth patch was, and reaction times were measured. As a control they were also tested on single patches of each color. Here are the results:
When the colors were displayed by themselves, there was no significant difference in reaction time, but when they were shown among three dark green patches, the light green patches were identified significantly faster. Thus, Navon and Kimchi argue, they have demonstrated that the Beck effect applies not only to shapes, but also to colors. This makes both explanations of how the effect works problematic.
The researchers argue that the real source of the effect might be in the difference between judging between multiple possibilities and a single possibility. An analogy might be pregnancy: “Are you pregnant or not?” is an easier question to answer than “are you pregnant with a single fetus or twins?”
D. Navon, R. Kimchi (2004). The Beck effect is back, now in color: A demonstration Psychonomic Bulletin and Review, 11 (1), 98-103