Women in Science Banner

Biography - Nadezhda Ladygina-Kohts

Beginning of the Nadezhda Ladygina-Kohts’s study
In 1935, Nadezhda Ladygina-Kohts published Infant Chimpanzee and Human Child, which focuses on the comparative study between the behavior of an infant chimpanzee and a human child. The book features texts and photographs comparing the expressions, perceptual abilities, and cognitive and emotional development of Joni, the infant chimpanzee, and Kohts’s son Roody [fig.1]. The series of ingenious experimentations conducted by Kohts were considered ahead of their time, and it exerted a profound influence on the development of modern comparative psychology, primatology, and cognitive science.[1] Ultimately, Kohts’s methods of cross-fostering, matching-to-sample, and the use of photomontages in the 1930s clearly demonstrated dissimilarities in instincts, memory and ways to express emotion between chimpanzees and humans.

Ladygina-Kohts as a female scientist
Born in 1889, Nadiya Ladygina-Kohts received her degree from Moscow University in 1917 with a specialization in comparative psychology. Kohts was still a student when she opened the Psychological Laboratory of the Darwin Museum that her husband, Alexander Fiodorovich Kohts, founded in 1907. Kohts’s major objective was to examine Joni’s perceptual and conceptual abilities in 1913. This was a perfect opportunity for Kohts because the theory of evolution proposed by Charles Darwin had always been her main interest since the early years of her research. Unfortunately, after approximately three years of study, Joni died of a respiratory illness in 1916. In 1925, Kohts’s own son, Roody, was born; around 1929, Kohts then began work on a comparative study based on the detailed descriptions in her diary records of Joni and Roody [2].

Frans B.M. de Waal, one of the most well-known primatologists in the world, believed that Kohts followed in “Charles Darwin’s footstep by offering a point-by-point comparison of the emotional expressions of a young chimpanzee and a human child.”[3]” De Waal appreciated Koht’s ingenious ways of studying the wide range of emotional responses in Joni, from jealousy and guilt to empathy and fierce loyalty to loved ones. De Waal also believed that although her cognitive and socio-emotional approach was far ahead of its time, Kohts is less well-known than some of the modern scientists perhaps because of her gender. However, Kohts’s studies have been recognized lately because of contemporary scientists continuing to use methods introduced in Kohts’s research to study primates’ behavior and intelligence [4].

Cross-fostering method: Instinct behavior
A great success of Kohts’s large-scaled research was mainly due to methods she developed in zoopsychology. In the beginning of Kohts’s comparative study, she introduced the cross-fostering approach, which represents a tradition of adopting anthropoid young primates to scientist families in order to systematically study their psyche and behavior.[5] Chimpanzees in particular were perfect research candidates for Kohts’s comparative study due to chimpanzees’ equivalent maturation processes with human infants.[6] In addition, the cross-fostering approach allowed the researchers to obtain both quantitative and qualitative observations because researchers can constantly note the subject’s behaviors through a long-term study.[7] Therefore, Kohts took advantage of cross-fostering techniques to study dissimilarities in instinct behaviors between infant chimpanzee, Joni, and her son, Roody.

For example, Kohts juxtaposed self-supporting instincts such as medical treatment behaviors between a human child and an infant chimpanzee. During illness, Kohts stated that the chimpanzee “Joni “works” on a sore spot himself, picking at it until it starts bleeding, pulling out splinters, and twitching from pain, and he nevertheless does not stop his manipulations.”[8]” In contrast to Joni, the human child is afraid to even to touch the spot because it may hurt. Once, Roody “stained his finger with iodine; he cried with all his strength, afraid to look at the finger and thinking that it was bleeding.”[9]”

Roody would refuse to take medication, while Joni took all medicine, including extremely smelly ones, very calmly. Kohts’s data demonstrated that although both Joni and Roody were raised by the same parents within the same household, the human child seemed to be more physically dependent when dealing with illness or pains than an infant chimpanzee at an early age of development. However, Kohts revealed that if the child’s injuries are not too serious such as if he scratches his hand or breaks his fingernails, the child is inclined to “examine the sore spots with his fingers or toes, with his lips, or with the tip of his tongue at the age from one to three years” similar to a chimpanzee.[10] Kohts observed that the child stops these manipulations at the slightest pain he senses in contrast to the chimpanzee. When the child gets older, he would rather hide his splinter than show it and ask elders to remove it for him. Surely, the child is not able, like the chimpanzee, to take the splinter out.

Moreover, Kohts emphasized the dissimilarity of behaviors associated with freedom instinct between human child and an infant chimpanzee. For example, Joni’s desire to come out of his cage, his rooms, and his home was very strong, according to Kohts. Interestingly enough, when Joni was set free, he liked to go to high places rather than run far away, which illustrated his passion for climbing. In contrast to Joni, the human child does not have a tendency for climbing when left alone; rather he satisfies himself at the ground level. Kohts observed that Joni can sit or walk on the roofs for hours alone, while the human child is unwilling to part with adults and he is not motivated to these lonely behaviors at the age of three.[11] Through Kohts’s observation, the desire to be freed from one’s own physical, mental space was highly common in an infant chimpanzee than a human child. Overall, Kohts’s ways of using cross-fostering technique in studying an infant chimpanzee’s instinct behaviors provided specific examples behind Joni’s mode of actions in her comparative study with a human child.

Sample-to-match method: Memory
After observing differences in instinct behaviors between the human child and an infant chimpanzee, Kohts then compared memory abilities utilizing a sample-to-match approach.
A way of testing the complexity of an organism’s short-term memory known as “matching-to-sample” was invented by Kohts and has become a standard procedure for primate testing.[12] In general, the sample-to-match method involves the: presentation of a sample object by an experimenter, symbolizing the command to select the similar object on the table and then observing the animal’s search; for the desired object; and their ultimate recognition of the correct object.[13] Robert Yerkes, a respected “American primatologists best known for his work in intelligence testing and in the field of comparative psychology in 1930s,” stated that although the method was not “entirely new in comparative psychology, it has never been used systematically, extensively, and with the degree of critical elaboration which Mrs.Kohts’s work exhibits.”[14] In Koht’s experiment, she held up an object in her hand and gave Joni a tidbit of food as a reward if Joni picked up the similar object sitting in an array of objects nearby. Moreover, Paul McGreevy, a faculty of veterinary science at the University of Sydney, noted that Joni was able to perform well on a version of task that tested for not only Joni’s short-term memory, but also the transfer from one sense to another.[15]

This is exemplified when “Kohts had Joni reach into a bag and select a specific object from several that were in the bag. Not only did this test Joni’s ability to discriminate objects by touch, it also tested Joni’s vision to match the sample held up by the experimenter.[16]” In addition, Kohts’s ingenious experimental technique prevented suggestions that she was providing Joni with visual cues via a Clever Hans effect. This effect “avoids experimental bias on research subject through double-blinded test; therefore, the results are purely based on the subject’s capability to succeed.[17]” Similar to Joni, the human child’s conditioned actions or language from auditory and visual-motor reflexes initially are mechanical, stereotypical, and inflexible.[18] However, when “accumulated and enriched in associations, they serve their purpose as means of communication with people around and promotes his mental development especially for the human child.[19]” In contrast to the infant chimpanzee, the child develops long-term memory after only one demonstration.

For example, the nine-month-old Roody grabbed a brush and accidently pricked his finger when Kohts showed him a brush. A week later, Kohts brought him the same brush and this time, Roody did not reach for it immediately. He, however, “first stared at it, tentatively extended his hand, touched the central metal wire of the brush, and only then touched the prickly hair.[20]” Through Roody’s situation, Kohts demonstrated that the human child was able to remember the pain he perceived a week ago and reacted differently when he encountered it a second time. Kohts claimed that while the chimpanzee shows “stereotypical conditioned reflexes that are predictable and are based on the chimpanzee’s experience, the human child often surprised her with a new conditioned reflex reaction that requires genuine work of thinking.”[21]” Kohts was astonished to discover that Roody memorized the first names and patronymics of all people in her household, while the chimpanzee Joni knew only her name and did not react to the names of other people in the household. Above all, the animal showed capacity for the formation of ideas, but these lasted in memory only a few seconds. Through the sample-to-match technique, Kohts illustrated that “chimpanzee has neither desire nor ability to give thought to what has already passed,” in contrast to the human child.[22]

Photograph plate method: Emotion
Throughout Kohts’s comparative study, she heavily focused on the facial emotions expressed by the infant chimpanzee and the human child. Of the various studies reported by Kohts, hundreds of fascinating photographs on facial expressions made the deepest impressions, distinguishing her as a scholar.[23] By applying photomontage technique, Kohts evaluated differences in facial emotion expressed by the infant chimpanzee and the human child despite their hardly noticeable, apparent similarities. For example, Kohts was able to distinguish minor differences in facial expressions of joy between the two infants by using method of photomontage. Kohts claimed that “during maximum laughter induced by tickling, the child and the chimpanzee open the mouth wide, [plate 81(6)] pulling the lips to the sides; at the same time, the child often bares the teeth of the lower and upper jaws,” which usually is not observed in the chimpanzee [fig 2].[24] Even during maximum laughter, only the upper edges of the chimpanzee’s canines or the upper edges of his lower teeth [plate 81(5)] are visible [fig.2].[25] Such minor differences in facial expression present in the infant chimpanzee and the human child would not be perceived as obvious by the reader without the help of Kohts’s photographs.

In addition, another difference pertains to the eyes during the expression of laughter in both infants. Kohts witnessed that in a child’s laughter invariably is accompanied by strong, uniform narrowing of his eyes [plate 26(6), 81(6)] [fig.3].[26] Sometimes, during maximum laughter, the human child’s eyelids close almost completely [plates 26(3), 26(4)] [fig.3]. In the case of a happy chimpanzee, Kohts witnessed two patterns: He “either opens his eyes wide, or slightly narrows the outer corners of the eyes [plates 2(4)-2(7), 81(5)] [fig.4].”[27]” In general, babies’ features are tiny, and the “subtle movements that make up their expression can change too quickly to be observed accurately with the unassisted eye.”[28]” Therefore, use of the photomontage technique helped Kohts to pinpoint out the dissimilarity in facial expression between the two infants.

Interestingly, the method of capturing photographs to demonstrate varieties of emotional reactions expressed in animals originated from Charles Darwin’s The Expression of the Emotions in Man and Animals. Darwin applied the photomontage technique to defend the argument that “emotion expressions are evolved and adaptive, and serve an important communicative function.”[29]” At the time of Darwin’s study, photography was still a relatively new art form. Nevertheless, Darwin believed that it would “hold an advantage over other forms of representation since its potential for capturing fleeting expressions with accuracy and detachment would prove more objective.”[30]” Similar to Kohts, Darwin also mentioned expression of emotional reaction during excessive laughter. However, Darwin focused on the physiological aspects, while Kohts emphasized general anatomical features relating to maximum laughter. For example, Darwin noted that during excessive laughter, the “whole body is often thrown backward and shakes, or is almost convulsed; the head and face become gorged with blood, with the veins distended; and the orbicular muscles contracted in order to protect the eyes.”[31]” Overall, Kohts visibly demonstrated the dissimilarity in emotional reactions that exist between the human child and the infant chimpanzee with the method of photomontage.

Kohts and Contemporary Primate Studies
Authentic and finely elaborated by Kohts, the methods of: cross-fostering, matching-to-sample, and photomontage have become an integral part of modern science. Contemporary scientists all over the world continue to use the matching-to-sample technique when studying a wide range of tests on animal cognition.[32] Moreover, the cross-fostering methodology was found to be especially valuable in studying language-trained chimpanzees in 1970-1990s. These experiments expanded and developed the data on the comparative behavioral “ontogenesis of human and anthropoid infants obtained by Kohts and suggested the ability of great apes to master human language on the level of two year’s old human child.”[33]” Ultimately, Koht’s pioneering observations serve as a continuing inspiration for many future primate studies.

Soo Kyun Hur

[1] Encyclopedia of the Norbert M. Seel., ed. Encyclopedia of the Sciences of Learning. (Springer Reference, 2011), 1708.
[2] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), xiii.
[3] Frans B.M. de Waal. “A Century of Getting to Know the chimpanzee.” Nature 437, no. 7055 (2005): 56.
[4] Ibid.
[5] Encyclopedia of the Norbert M. Seel., ed. Encyclopedia of the Sciences of Learning. (Springer Reference, 2011), 1711.
[6] Virginia M. Gunderson and Karyl B. Swartz. “Effects of Familiarization Time on Visual Recognition Memory in Infant Pigtailed Macaques (Macaca Nemestrina)." Developmental Psychology 22, no. 4 (1986), 477.
[7] Steve Smith. “Infant cross-fostering in rhesus monkeys (Macaca mulatta): A procedure for the long-term management of captive populations.” American Journal of Primatology 11, no. 3 (1986), 229.
[8] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), 228.
[9] Ibid.
[10] Ibid.,229.
[11] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), 239.
[12] Juan Carlos Gomez. Apes, Monkeys, Children and the Growth of Mind. (Massachusetts: Harvard University Press, 2004), 128.
[13] David MacCahnan. “Characters and Personality.” Journal of Personality 6, no.4 (1938), 342.
[14] Robert M. Yerkes and Alexander Petrunkevitch. “Studies of Chimpanzee Vision by Ladygina-Kohts.” Journal of Comparative Psychology 5, no.1 (1925), 102.
[15] Paul McGreevy and Robert Boakes. Carrots and Sticks: Principles of Animal Training. (Massachusetts: Cambridge University Press, 2008), 93.
[16] Ibid.
[17] Dario Martinelli. “Language and Interspecific Communication Experiments: A Case To Re-Open?” Introduction to Biosemiotics (2007), 488.
[18] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), 342.
[19] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), 342.
[20] Ibid., 341.
[21] Ibid., 344.
[22] Robert M. Yerkes and Alexander Petrunkevitch. “Studies of Chimpanzee Vision by Ladygina-Kohts.” Journal of Comparative Psychology 5, no.1 (1925), 107.
[23] Lenny van Rosmalen. “An Unexpected Admirer of Ladygina-Kohts.” History of Psychology 14, no.4 (2011), 413.
[24] Ladygina-, Nadezhda Ladygina-Kohts, Infant Chimpanzee and Human Child, edited by Frans B. M. de Waal. (Oxford University Press, Oxford, 2002), 244.
[25] Ibid.
[26] Ibid., 224.
[27] Ibid.
[28] Phillip Prodger. Darwin’s Camera: Art and Photography in the Theory of Evolution. (New York: Oxford University Press, 2009), 113.
[29] Ursula Hess and Pascal Thibault. “Darwin and Emotion Expression.” American Psychologist 64, no.2 (2009), 120.
[30] Sp Coll Dougan. "University of Glassgow." The Expression of the Emotions in Man and Animals. Last modified November, 2009. Access date April 29, 2012. http://special.lib.gla.ac.uk/exhibns/month/nov2009.html.
[31] Charles Darwin. The Expression of the Emotions in Man and Animas. (New York: Oxford University Press, 1998), 214.
[32] Encyclopedia of the Norbert M. Seel., ed. Encyclopedia of the Sciences of Learning. (Springer Reference, 2011), 1711.
[33] Encyclopedia of the Norbert M. Seel., ed. Encyclopedia of the Sciences of Learning. (Springer Reference, 2011), 1711.