James L. Pate

Delay of gratification in chimpanzees (Pan troglodytes)

Delay of gratification in 3 chimpanzees (Pan troglodytes) was examined by using a paradigm based on research with children. The chimpanzees either pressed a door-bell button during a trial and received one reward (the immediate reward) or did not press the doorbell and received another reward (the delayed reward). Two chimpanzees were language-trained, and a 3rd was non-language-trained. Foods (one more-preferred and one less-preferred), photographs of those foods, or lexigrams representing those foods were presented to the chimpanzees. All 3 chimpanzees delayed gratification when foods were physically present. One language-trained chimpanzee also delayed gratification with lexigrams present, and the 2nd language-trained chimpanzee delayed gratification in all three conditions. Language competence and early rearing are proposed as explanations for the different performances of these chimpanzees.

Addendum to «summation in the chimpanzee (Pan troglodytes)»

Rumbaugh, Savage-Rumbaugh, and Hegel (1987) reported that two chimpanzees (Pan troglodytes) could select, with better than 90% accuracy, the greater of two paired quantities of chocolate chips. In that study, no one quantity of chocolates (from 0 through 5) was used in both pairs on a given trial. We investigated the effect of having one quantity in common (CQ) in both pairs. Whether the other quantities (OQs) of chocolates were both less than or greater than the CQ, summation still occurred. Accuracy was primarily a function of the ratios of sums to be differentiated. This finding substantiated the earlier conclusion that summation was based on both quantities of each pair and not on some simpler process such as the avoidance of the tray with the smallest single amount or selection of the tray with the single largest amount.

Assessment of Borderline Personality Disorder Using the MMPI-2 and the Personality Assessment Inventory

The usefulness of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the. Personality Assessment Inventory (PAI) in the classification of patients diagnosed with Borderline Personality Disorder (BPD) was investigated. Twenty-two female inpatients diagnosed as having BPD and 22 female student control participants participated in the study. Those who scored 70 or above on the Borderline Features (BOR) scale of the PAI were classified as BPD. For the MMPI-2, participants with profile configurations of 8-4-2, 8-2-4, 8-4-7, or 8-2-7 were classified as BPD. Eighty-two percent of the patients and 77% of the students were classified correctly using the PAI, whereas 9% of the patients and 95% of the students were classified correctly based on the MMPI-2. The discriminant function for the selected scales of the PAI classified 8G% of the participants correctly, and the discriminant function for the selected scales of the MMPI-2 classified 84% of the participants correctly. This suggests that both tests include items that discriminate between the two groups. Overall, the classification of participants based on the BOR scale of the PAI was more accurate than the classification of participants using the profile configurations of the MMPI-2. Implications for the assessment of BPD are discussed.

A chimpanzee’s (Pan troglodytes) long-term retention of lexigrams

In this experiment, a chimpanzee’s (Pan troglodytes) long-term retention was examined. The chimpanzee, Lana, was trained to use lexigrams (geometric symbols representing linguistic units) for foods, colors, and objects when she was 2 years of age. At the age of 27, her recognition of three sets of lexigrams was examined. One of these sets (long term lexigrams) included five object lexigrams, one color lexigram, and one food lexigram, none of which had been seen by Lana for more than 20 years. The second set (different-referent lexigrams) contained lexigrams that are still present on current lexigram keyboards, but had been assigned new referents. The third set (same-referent lexigrams) contained lexigrams that had been kept on the keyboards Lana had used and that had retained the same referents. A food, a colored square, or an object was presented, and Lana had to select, by using a joystick, a lexigram on a computer screen. Lana chose the correct lexigram at a level significantly greater than chance for five of the seven lexigrams that she had not seen for more than 20 years.

Sequential responding and planning in chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta).

Chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta) selected either Arabic numerals or colored squares on a computer monitor in a learned sequence. On shift trials, the locations of 2 stimuli were interchanged at some point. More errors were made when this interchange occurred for the next 2 stimuli to be selected than when the interchange was for stimuli later in the sequence. On mask trials, all remaining stimuli were occluded after the 1st selection. Performance exceeded chance levels for only 1 selection after these masks were applied. There was no difference in performance for either stimulus type (numerals or colors). The data indicated that the animals planned only the next selection during these computerized tasks as opposed to planning the entire response sequence.

Alternation behavior of children in a cross-maze

Seventy-five children of preschool age were observed in a cross-maze. The frequency of alternation increased with age for the Ss who started both trials from the same start position but did not change across age for the Ss who started the two trials from opposite start stems. Running time decreased with increasing age under both conditions.

Extra-maze pre-exposure and choice behavior

Sixty albino rats were given a single test trial in a black-white T-maze following exposure to either a black or a white stimulus. It was found that a significant number of animals chose the non-exposed brightness in the maze. This is the first study to demonstrate that exposure to a stimulus outside the choice apparatus affects the choice behavior. Exposure time was not a significant factor in determining the animal’s choice but this may well have been the result of using long exposure times. A marked brightness preference was also noted.

The language-like behavior of Lana chimpanzee: Is it merely discrimination and paired-associate learning?

The productions of Lana chimpanzee during an experiment that lasted 25 days were analyzed from a “stock sentence” approach and from a phrase-structure approach. In answering questions posed by the experimenter and in making requests, Lana’s productions seemed to be best explained in the phrase-structure approach, in which phrases, rather than individual lexigrams, served as lexical units. Phrases were transposed, both correctly and incorrectly, and were combined to convey different meanings. Thus, it was concluded that Lana’s productions require a more complex model than the simple discrimination learning model suggested by Thompson and Church (1980).

Budgeting decisions as a function of framing: an application of prospect theory's reflection effect

Many decisions based on accounting data can readily be framed in relation to varying reference points. This fact suggests possible framing bias through prospect theorys reflection effect, past tests of which have been inconsistent in various contexts. The main purpose of this study was to test for the reflection effect in a budgeting decision as well as for the possible influence of decision-makers’ specific training, present work experience, level of past work experience, and the computation of decision alternatives’ expected value on decision outcomes. The sample consisted of 260 responses from graduate business students. In both positive and negative domains, there was a shift to greater risk-taking when framing was shifted from positive to negative. Subjects’ specific training, present work experience, level of past work experience, and the computation of expected value of alternatives all failed to produce significant effect on decisions.

Brightness and direction as cues for spontaneous alternation behavior

In a study designed to test the relative effectiveness of spatial direction and brightness cues for spontaneous alternation, 29 rats were run in a grey T-maze with black and white inserts in the goal arms. Odor-trail cues were eliminated by changing the paper flooring of the maze between trials and between Ss. In Part A, the Ss received two daily trials, with the inserts switched between Trials I and 2 to contrast direction and brightness cues-to alternate spatial direction, a rat had to repeat brightness. Insignificant alternation occurred with this procedure. In Part B, when the Ss were forced four times to the same direction and stimulus insert and then were given a free trial with the inserts switched to contrast cues, significant alternation of spatial direction was observed. In Part C, when Ss received four forced trials to opposite arms but to the same stimulus insert, brightness was alternated significantly. The alternation rates in the three parts of the experiment were interpreted as evidence that brightness is an important cue for spontaneous alternation.