How to Coach Yourself and Others Beware of Manipulation | Page 215
deck of cards (Teszka et al., 2011). Here linguistic social cues (i.e., asking a question) were used to
prevent participants from detecting this change.
Two types of hand motion are used to control the audience’s attention. Slow, circular hand motions are
good at engaging and keeping attention, while fast, straight ones are useful for quickly diverting it from
one spot to another. The scientific basis of this difference is unknown, says Martinez-Conde. But she
plans to find out.
Illusion
Misdirection can also make people perceive illusory events that have not occurred. For example,
Triplett (1900; Kuhn and Land, 2006) developed the vanishing ball illusion in which a magician is seen
throwing a ball up in the air a couple of times, before merely pretending to throw it. Most of the
observers claimed to have seen a “ghost ball” leaving the hand on the final throw, thus illustrating that
people’s perception of an event is largely influenced by expectations, rather than the physical presence
of the ball.
Cui et al. (2011) developed a related paradigm in which participants were repeatedly asked to view a
video clip of a magician tossing a coin from one hand to the other. On some of the trials the coin was
tossed for real, whilst on the other half of the trial the magician merely pretended to toss the coin. On a
large proportion of trials, participants claimed to have seen the coin fly from one hand to the other,
even though it was not physically present.
Numerous studies have now demonstrated that misdirection provides an extremely effective way of
manipulating what people see. Rather surprisingly, these studies have consistently shown that people’s
detection of the event (i.e., the lighter or cigarette drop) was independent of where they were looking,
thus demonstrating that misdirection generally relies on manipulating covert (i.e., attention in the
absence of eye movements), rather than overt attention (i.e., were people look). These studies also
clearly illustrate that whilst covert and overt attention can be dissociated in space (Posner, 1980), there
is a clear temporal link between the two.
214