Despite overall physiological bilateral symmetry, many species exhibit

Despite overall physiological bilateral symmetry, many species exhibit lateralized biases, i.e., preferences for right- or left-oriented behavior. When approaching prey, for example, some predator species favor their right eye; some prey species respond more quickly when their left eye detects a predator. Similar behavioral asymmetries occur in humans. Most notable is right- and left-handedness; less notable is the tendency to turn right when entering a room. Paul Farnsworth found that more successful students tended to choose seats near the front, a little to the right. He argued that external factors such as teacher location might have affected this lateral bias. But it is now known that processing differences between the two brain hemispheres can also contribute to behavioral asymmetries.

George Karev found that when presented with a movie theater seating diagram, right-handed people were more likely than left-handed people to choose a seat on the right, facing front. But he hypothesized that, since the right hemisphere processes visuospatial and emotional information, the people who chose right-side seats did so because that would put the screen in their left visual field, optimizing information flow to the right hemisphere.

Although the right hemisphere is thought to be dominant in processing emotion, some evidence suggests that the left hemisphere plays a role. The valence model proposes that the left and right hemispheres process positive and negative emotion respectively, while the approach-withdrawal model posits that the left hemisphere processes emotion expressed in approach behavior and the right hemisphere processes emotion expressed in withdrawal behavior.

Victoria Harms and colleagues suggested that since a paper seating plan was used in the theater-seating studies by Karev and others, the exhibited preference might be due simply to handedness: people choose the same side of the paper as their favored hand. Consequently, the Harms research was designed to study choices in an actual movie theater. Also, hoping to distinguish between various explanations, they studied seating choices for comedies (presumed to contain positive emotional content), dramas (presumed to contain negative emotional content), and documentaries (presumed to have balanced emotional content). They found significant—though not universal—preference for seats on the right, facing front, regardless of movie genre and of handedness.

1. Which of the following statements concerning the valence model and the approach-withdrawal model most accurately reflects information provided in the passage?
A. Each of the two models implicates both hemispheres of the human brain in the processing of emotion.
B. Both models suggest that cognitive information is processed by only one brain hemisphere in humans.
C. Each of the two models explains how emotional information affects the processing of cognitive information in the human brain.
D. Both models seek primarily to describe how emotion is expressed in behavior.
E. The assumptions of both models concerning the processing of visuospatial information are identical with those made by Karev.

2. Which of the following is most strongly supported by the findings of the Harms study?
A. Right-handed people shown a seating plan tend to choose seats on the right side of the seating diagram whether it shows the front seats at the top or the bottom.
B. The seating choices of those attending a movie, regardless of the genre, have little impact on how well the movie is understood.
C. The seats preferred by most left-handed people attending a movie are on the opposite side of the theater from those preferred by most right-handed people.
D. Well-made documentaries contain significantly more visuospatial content than emotional content.
E. In theaters full to capacity and with left-right symmetry in their seating diagram, not all audience members get to sit on the side of the theater they most favor.


3. The author's purpose in mentioning prey and predators is to
A. illustrate how lateralized bias in the behavior of some species can facilitate or impede survival
B. provide examples illustrating the prevalence of lateralized bias among animal species
C. indicate a difference between humans and other species with respect to vision-dependent behaviors
D. provide examples illustrating the geometric concept of asymmetry
E. suggest a hypothesis about the mechanisms by which lateralized biases in behavior evolved


4. According to the passage, Karev's hypothesis suggests which of the following about people's choices of seating in movie theaters?
A. They are random.
B. They are seldom preceded by deliberation.
C. They depend primarily on habits formed in childhood.
D. They are primarily affected by variations in visual acuity.
E. They often function to facilitate processing of certain kinds of information.