Suomi is the Head of the NIH National Institute of Child Health and Human Development, Laboratory of Comparative Ethology, a monkey lab.
Stephen Suomi is, perhaps, the most well known of Harry F. Harlow’s PhD students. Melinda Novak and Gene Sackett, also Harlow’s grad students, made presentations as well.
[Suomi’s PhD committee included Charles T. Snowdon who also made a number of presentations. Snowdon was a primate vivisector at the University of Wisconsin and was the subject of fawning admiration at the ASP conference.
[Session 3: Outstanding Mentor Symposium honoring Chuck SnowdonBut this essay is about Stephen J. Suomi.
Organizer: Anne Savage
CHUCK SNOWDON’S CONTRIBUTIONS TO CALLITRICHID BIOLOGY: COMMUNICATION, REPRODUCTION, AND CONSERVATION A. Savage, T. E. Ziegler, J. A. French.
LESSONS FROM MY MENTOR, CHARLES SNOWDON T. A. Porter
DR. CHARLES T. SNOWDON'S METHOD OF RAISING FUTURE SCIENTISTS R. S. Roush.]
The title of Suomi’s 1971 doctoral thesis is Experimental Production of Depressive Behavior in Young Monkeys.
The following quoted passages come from that document. The two images are from “From thought to therapy: lessons from a primate laboratory.” Harlow HF, Harlow MK, Suomi SJ. Am Sci. 1971 Sep-Oct;59(5):538-49.
The goal of this research was the production in young monkeys of behaviors similar to those exhibited during the despair stage of maternal separation but for longer periods of time, in different situations, and among monkeys subjected to a variety of rearing conditions.
The primary purpose of the first experiment was to determine if the protest-despair-recovery reaction exhibited by monkeys separated from their mothers would be elicited via separation procedures not involving monkey mothers2 male and 2 female rhesus monkeys were separated from their mothers at birth and reared for the first 15 days of life in a laboratory nursery.
At 15 days old they were placed as a group in a cage 6’ x 3’ x 4’ with 2 blocks of wood and 2 plastic balls (called play objects), and 4 towels.
At 90 days old, the first series of separations was begun.
The four monkeys were separated from one another and housed in wire mesh cages 2.5 x 2.5 x 2.5 for four days. The monkeys could see and hear each other, but could not make physical contact. Each cage had one play object and one towel.
They were then returned to their group for 3 days.
This went on for 12 weeks. Isolated for 4 days, reunited for 3 days. Isolated for 4 days, reunited for 3 days.
At 6 months old, they were returned to their group cage for 6 weeks, after which they went through 8 more weeks of isolation and reunion.
Three clear-cut findings emerged from this study.
First, the reaction to maternal separation previously described for both human and monkey infants were clearly exhibited during the weekly separation cycles by the experimental subjects.
Second, the monkeys did not adapt to the multiple separations. For each separation series the monkeys reactions to the latter separations were at least as severe as their reactions to the first separations in the series.
Finally, an overall effect of the repetitive separations was an almost complete arrest of maturation of social behaviors in the monkeys.
Were the monkeys depressed?
Only a qualified yes may be given. Certainly the behaviors exhibited during the latter part of each separation—the high levels of passive self-directed behavior and the low levels of locomotion and exploration—paralleled the description of withdrawal among human children in analogous situations while the maturational arrest in monkeys has a possible parallel in the human retardation of development.
The technique of repetitive infant-infant separation yielded promising results for production of a depressive syndrome in monkey subjects....
A special device was built…this apparatus was termed the vertical chamber.4 rhesus monkeys. One male 15 months old, one male 6 months old, one female 13 months old, and one female 9 months old were separated from their mothers at birth. They were individually housed in a bare 2.5 x 2.5 x 2.5 wire mesh cage, where they could see and hear, but not have physical contact with the other monkeys.
Each subject was placed alone in the vertical chamber for 20 days, then returned to his or her home cage for 7 days.
Then the monkey was put back in the chamber for 10 days and then returned to his or her home cage.
Vertical chamber confinement had a profound and prolonged effect upon the subjects’ behaviors.
Self-clasping, rocking and huddling had dramatic increases following their return to the home cage after each period of chamber confinement.
Locomotion dropped sharply following vertical chamber confinement. Environmental exploration was virtually absent. These behaviors did not dissipate over time.
Behavioral changes of a striking nature could be rapidly produced via vertical chamber confinement. Altered levels of behaviors persisted long after the subjects had been removed from the chambers.
On the basis of the findings of the previous experiment, I decided to compare the psychopathology- producing potential of the vertical chamber apparatus with the isolation procedures.Suomi explained that monkeys were to be reared for the first three months of their lives within the vertical chambers, then subjected to extensive post incarceration testing to determine if any lasting behavioral anomalies would be disclosed. However, it was discovered that infant monkeys could not be maintained effectively in a vertical chamber until they are 45 days old. The decision was made to incarcerate subjects beginning at this age for a total of 45 days.
4 male rhesus monkeys were separated from their mothers at birth. They spent the first 45 days of life in a lab nursery.
At 45 days of age each subject was placed in the vertical chamber for 45 days (6.5 weeks.) They were then removed from the vertical chamber and placed in a bare wire mesh cage.
The results of experiment 3 indicated that the 45-day period of vertical chamber confinement early in life produced severe and prolonged psychopathological behavior of a depressive nature in the rhesus monkey subjects.After being removed from the chambers, the monkeys self-clasped and huddled at enormously elevated levels. The monkeys locomoted and explored significantly less than both control groups and exhibited essentially no socially directed behaviors. Their behaviors could be described as a “severe caricature of the despair stage exhibited by monkeys separated from mothers or peers.”
It is clear that behavioral disturbances of a stable and lasting nature were produced by vertical chamber confinement of a remarkably short time. The further use of vertical chamber incarceration as a technique for production of depressive behavior thus seemed justified.
Having established that the use of the vertical chamber was an effective technique for production in monkeys of psychopathological behavior of a depressive nature, the next step was to combine the manipulation of chamber incarceration with separation procedures. A logical combination was repetitive peer separation involving chamber confinement during the periods of separation.4 rhesus monkeys, 2 male and 2 female, were separated from their mothers at birth, reared in laboratory nursery for first 15 days of life.
At age 15 days, monkeys were placed in a group of 4 in a cage 6 x 3 x 4 with four cloth towels, and two balls and two pieces of wood. They were undisturbed until they were three months old.
At 3 months of age, the monkeys spent 4 days of separation, three days of reunion, then 4 days of separation, then 3 days of reunion. This occurred 12 times.
Like experiment 1, they then had a 6-week reunion followed by 8 more weeks of the separation-reunion routine.
However, when separated, the monkeys were not individually housed in single cages as in the first experiment. Instead they were placed in individual vertical chambers where they could hear, but neither see nor touch each other.The monkeys in this study were subjected to 20 four-day periods of separation during which they were confined to vertical chambers. The monkeys were not observed when they were confined to the vertical chambers.
Monkeys confined to the vertical chamber during repetitive infant-infant separation exhibited protest, despair, and recovery reactions to separation and showed severe maturational arrest.
The monkeys vocalized at exceedingly high levels and moved about inside the vertical chambers for approximately the first day of each separation.
By the third and fourth days of separations, however, the monkeys typically assumed a huddling position in a corner of the chamber.
Chamber confinement made socially abnormal more abnormal while causing relatively normal subjects to become far less normal....
My goal of the reliable production of stable depressive syndromes in young monkey subjects was attained by these studies.
Experimentation with therapeutic agents and techniques utilizing human patients is seriously hampered by lack of experimental control and by sound ethical constraints. No such problems exist for the monkey researcher.
My research has demonstrated that depressive behavior of a stable and lasting form can be induced reliably in young monkey subjects. Having established the behavioral basis for an animal model it is now the task of further research to make the experimental model useful.”
Here is one of the papers presented at the 2007 ASP conference:
MONOAMINE OXIDASE A (MAOA) GENE PROMOTER VARIATION INTERACTS WITH EARLY REARING CONDITION TO INFLUENCE THE BEHAVIORAL RESPONSE TO SOCIAL SEPARATION IN RHESUS MACAQUES (MACACA MULATTA)
M. L. Schwandt (1), T. K. Newman (2), S. J. Suomi (3), J. D. Higley (4), M. Heilig (1) and C. S. Barr (1)
(1) NIH/NIAAA, Laboratory of Clinical and Translational Studies, PO Box 529, Poolesville, MD, 20837, USA, (2) University of Cape Town, South Africa, (3) NIH/NICHD, Laboratory of Comparative Ethology, (4) Brigham Young University, Department of Psychology
Recent studies in humans have found associations between a polymorphism in the monoamine oxidase A (MAOA) promoter region and depression and anxiety disorders. In this study we investigated the effects of MAOA genotype and early rearing experience on the behavioral response to social separation stress in infant rhesus macaques. Six-month old monkeys (n=157; 89 females, 78 males) underwent four consecutive four-day long separations, with each followed by three days of reunion. Peer-reared (PR) monkeys were separated from their peers, while mother-reared (MR) monkeys were separated from their mothers. Behavioral data were collected and subjected to factor analysis and analysis of variance (ANOVA). Genotypes were clustered based on MAOA enzymatic activity (high vs. low). There were significant interactions of rearing and genotype on “depression” (inactivity and self-directed behaviors) in both males."
Thirty-five years after “earning” his doctorate, Suomi continues to separate baby monkeys from their mothers and document the results. Suomi is a highly regarded primate researcher; highly regarded by other sadists also calling themselves primatologists.