Thomas A. Looney

Aggression induced by intermittent positive reinforcement

Mammalian and non-mammalian species engage in aggressive behavior toward animate and inanimate targets when exposed to intermittent access to a positive reinforcer. This behavior, called extinction- or schedule-induced aggression, typically includes a biting or striking topography that inflicts damage on a target. This paper critically reviews research and theoretical issues concerning such aggression and suggests directions for future investigation.

A sequential feature-positive effect using tone as the distinguishing feature in an autoshaping procedure

Four groups of pigeons were exposed to an autoshaping procedure in which all trials were signaled by a green key light. A tone signaled a food trial for the two tone-positive groups and a no-food trial for the two tone-negative groups. The tone preceded and terminated with green light onset for the two sequential groups and began and ended with the green key light for the two simultaneous groups. The sequential tone-positive group acquired the discrimination faster than the other groups. Asymptotic discrimination was best in the sequential tone-positive and simultaneous tone-negative groups. Relatively few responses occurred on the green key in the simultaneous tone-positive group. The relationship of these results to other studies of the feature-positive effect are discussed.

Another look at “superstitions” in pigeons

Pigeons were exposed to fixed-time schedules of food delivery. The “ superstitious” behaviors observed were stable within subjects but differed markedly across subjects. These results are consistent with Skinner’s (1948) study but not with the data reported by Staddon and Simmelhag (1971) or Timberlake and Lucas (1985). However, our study was not an adequate test of Skinner’s hypothesis concerning the development of the various behaviors observed. Tests of his view are proposed.

Effects of the presence of a home-chamber target on experimental-session attack

Abstract A pigeon showed similar high rates of attack in the presence and absence of a fixed-time 90-sec food schedule, thus, raising the question of whether the attack was schedule-induced. The subsequent availability of a home-chamber target reduced the level of attack in both schedule and no-schedule sessions but did not alter the similarity of response rates in these conditions. The level of attack during a 25-min session was approximately the same as that during 15.5 hr in the home chamber. It was substantially greater than that during any 25-min period within the home chamber including the period following the daily feeding in a no-session condition. It is suggested that initially the attack was schedule-induced and then became conditioned to the experimental chamber. Implications of this interpretation are discussed as is the relevance of the methodology to studies of other adjunctive behaviors.

Schedule-induced attack as a function of length of exposure to a fixed-time 90-sec schedule

Twenty-four White King pigeons were exposed to a fixed-time (FT) 90-sec schedule of food presentation. For half of the subjects, a pictorial target was presented during the second session with the FT 90-sec schedule and throughout the remainder of the experiment. For the remaining subjects, the target was not made available until Session 26 with the FT 90-sec schedule. During early target availability, more subjects attacked in the late introduction condition. After extended exposure to the reinforcement schedule, however, similar numbers of subjects attacked in the two groups, eight in the early and nine in the late introduction group. The data suggest that when subjects are exposed only to a reinforcement schedule of moderate density, extended exposure with or without the target increases the probability that they will subquently attack the target.

A comparison of schedule-induced attack in White King and White Carneaux pigeons

The following conditions were presented to 12 White King and 12 White Carneaux pigeons: a fixed-time (FT) 90-sec food schedule, no food, and a return to the FT schedule. Schedule-induced attack against a pictorial target was sustained throughout the experiment for 10 White Kings and 4 White Carneaux. These results are consistent with other studies using either White Kings or White Carneaux with a pictorial target and strongly support the conclusion that White King is the more aggressive strain.

Attack during time-out from a fixed-interval schedule in pigeons

Deweese (1977) reported that when a time-out followed food delivery on a fixed-interval 180-sec schedule, squirrel monkeys did not attack until after the time-out. A similar procedure was employed with pigeons in the present study, with different results. It was demonstrated that the time-out stimulus exerted control over food-key responses but did not attenuate attack. In addition, when subjects were subsequently allowed to initiate time-outs, responding on the time-out key was not maintained. The results of the present study support the conclusion that the time-out stimulus was aversive.

Mirror control of responding on fixed-ratio schedules in pigeons

One of three pigeons exposed to multiple FR FR reinforcement schedules attacked a mirror target during postreinforcement pauses preceding the higher fixed ratio schedule. The same mirror-image stimulation, on the other hand, reduced reinforcement rate for all three pigeons by selectively increasing postreinforcement pauses preceding the higher fixed ratio schedule. This indicates that in studies of reinforcement schedules with pigeons, mirror-image stimulation from surfaces commonly present in standard test chambers (e.g., one-way mirrors, metal walls) may interact with schedule parameters to control postreinforcement behavior other than attack.