Martin Block


Psychologists have recently undertaken the exploration of questions related to animal personalities by objectively assessing the personalities of a variety of mammals. The current study used two common broad research strategies to characterize the personalities of a group of four female Western Lowland gorillas living at the Franklin Park Zoo in Boston. This group - consisting of a mother with her newborn, her 5-year old offspring, and a older unrelated female - were observed over a period of one year. The first personality assessment technique involved descriptions of individual differences under undisturbed conditions and when novel objects were introduced using an ethogram that contained specific behavioral units. The second technique employed two, more subjective rating scales typically used in assessing human personality characteristics: The Gorilla Behavior Index and a variation of the Q-sort Test. These measurements and assessment tools were used to develop personality profiles of each gorilla and to compare the personality of the infant gorilla to her older sister and to her mother to look for possible familial traits. Because the newborn female gorilla was born with a metabolic bone disorder, she provided a rare opportunity to track the behaviors of a gorilla developing under the challenges associated with early abnormal bone growth and to look for any abnormal ontogenetic behavioral patterns. Analyses of the infant's developmental pattern revealed several ontogenetic markers that were similar and different from the typical gorilla infant pattern found in other studies and from her sister's first year pattern of development. For the personality results, analyses of the objective behavioral measures and subjective personality tests indicated which traits were most reliable and, using those traits, identified several possible relationships among the personality profiles of the three female family members.

Date Accepted


Publication Date



gorilla, personality, development

Degree Grantor

Northeastern University

Rights Holder

Irene Bukh

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