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In the late 19th and early 20th centuries, Charles Henry Turner (1867–1923) established a research program that was in sharp contrast to prevailing ideas regarding animal behavior and cognition. Despite facing almost insurmountable barriers because of his African American ethnicity, he published more than 70 papers, including several in Science (1–3), on comparative brain anatomy in birds and invertebrates, individual variation of behavior and learning competences, and intelligent problem-solving in a large variety of animals, at a time when the dominant ideas only credited animals with the simplest of learning abilities. But his discoveries and conceptual advances failed to gain the recognition they deserved, and his works were later all but forgotten—indeed, some recent animal cognition research has reinvented wheels that had already been fashioned by Turner.
Charles H. Turner, pioneer in animal cognition
An African American scientist’s early discoveries are forgotten for all the wrong reasons
By Hiruni Samadi Galpayage Dona
and Lars Chittka
In the late 19th and early 20th centu-
ries, Charles Henry Turner (1867–1923)
established a research program that was
in sharp contrast to prevailing ideas re-
garding animal behavior and cognition.
Despite facing almost insurmountable
barriers because of his African American
ethnicity, he published more than 70 pa-
pers, including several in Science (13), on
comparative brain anatomy in birds and in-
vertebrates, individual variation of behavior
and learning competences, and intelligent
problem-solving in a large variety of animals,
at a time when the dominant ideas only cred-
ited animals with the simplest of learning
abilities. But his discoveries and conceptual
advances failed to gain the recognition they
deserved, and his works were later all but
forgotten—indeed, some recent animal cogni-
tion research has reinvented wheels that had
already been fashioned by Turner.
Charles Darwin (1809–1882) and George
Romanes (1848–1894) were famously gener-
ous in attributing intelligent behavior and
mental abilities to animals, but their mus-
ings were largely based on observation and
inference. The predominant experimentalist
theories of animal behavior in the early 20th
century, however, largely rejected notions
of advanced animal intelligence or insight.
Early ethologists such as Oskar Heinroth,
Charles Whitman, and Wallace Craig focused
instead on innate behavior and imprinting,
a simple form of learning. Where problem-
solving was observed, such as when ani-
mals open puzzle boxes, behaviorists such as
Edward Thorndike proposed that this ma-
terialized as a result of trial and error, not
insight or understanding of the nature of
the challenge. None of these scientists were
interested in individual variation of behav-
ior. Enter Charles H. Turner, who took seri-
ously Darwin’s assertion of the importance of
individual variation as well as the idea that
humans were not the only intelligent animal
species. But Turner backed up this possibility
with a rigorous experimental approach.
Turner was born just 2 years after the
end of slavery in the United States in 1865.
He obtained his M.Sc. from the University
of Cincinnati in 1892 (4). In the same year,
the 25-year-old published two single-author
papers in Science—one of which was a short
version of his B.Sc. work on the comparative
anatomy of bird brains, whose relative size
and complexity he compared with those of
reptiles (1). Turner’s verdict was, “When we
compare the brain of a crow or a titmouse
with the brain of a snake or a turtle, it is no
longer a marvel that birds bear towards their
reptilian cousins the relation of intellectual
giants to intellectual dwarfs” [(1), p. 16]. The
same year also saw the publication of an-
other remarkable study on variations in web
building by gallery spiders (5) that contained
key ingredients of Turner’s distinct interpre-
tation of animal behavior that was to accom-
pany his entire body of work. Like many of
his future papers, the study interfaces care-
ful field observations with meticulously con-
trolled laboratory work. Contrary to the still-
popular view that spider web construction
is a prime example of invertebrates’ robotic,
repetitive action patterns, Turner reported
variation between individuals in adapting
their construction to the geometry of avail-
able space and the functionality in captur-
ing prey: “we may safely conclude that an
instinctive impulse prompts gallery spiders
to weave gallery webs, but the details of the
construction are the products of intelligent
action” [(5), p. 110]. In the year of his Ph.D.
(1907), Turner published on associative and
spatial learning in ants and reported individ-
ual learning curves of their performance (6).
Turner’s focus on individual differences in
behavior is a constant theme in his studies.
It is deplorable that the now-popular field of
“animal personality” has taken so little no-
tice of Turner’s trailblazing approach.
The list of Turner’s discoveries and in-
sights that should have garnered attention,
but did not, is long. Every student of animal
behavior knows Nikolaas Tinbergen’s study
from 1932 on spatial learning, in which the
later Nobel laureate (awarded for studies of
individual and social behavior in animals)
first marked a beewolf’s nest entrance with
pine cones, then moved them to demonstrate
that the insect was guided by a memory of
the landmarks (7). But it is mostly unknown
that Turner had already published similar
findings in 1908, observing a solitary bur-
rowing bee whose nest entrance was close to
a discarded Coca Cola bottle cap. When the
cap was moved to a nearby location next to
an artificial burrow that Turner had made,
the bee crawled into that burrow without
hesitation—indicating, just as in Tinbergen’s
experiments, that the insect had a memory
for landmarks rather than, for example, be-
ing guided by an instinct to follow the scent
of the nest (8).
In 1912, in a study that explored how a prey-
carrying walking wasp finds its way home
around obstacles in the path, Turner explic-
itly confronted Thorndike, affirming that the
wasp’s behavior is not explicable by trial-and-
error learning and is instead consistent with
a form of intentionality and an awareness of
the desired outcome of the wasp’s actions (9).
Moreover, Turner found that an ant stuck on
a small island began assembling a bridge to
the “mainland,” using three different mate-
rials (10). The ant’s behavior could not eas-
ily be explained by then-popular notions of
instinct or trial-and-error learning; instead,
the ant appeared to appreciate the nature of
the problem, imagined a solution, and then
worked toward this goal.
The view that animals are capable of in-
sightful problem-solving was also apparent
in Turner’s interpretation of his field obser-
vations of the hunting behavior of a snake
pursuing a lizard (3). The lizard had escaped
up a tree and looked downward where it ex-
pected the snake to launch the next attack.
The snake, which had been pursuing the liz-
ard for some time, instead ascended another
tree, crossed over when it had reached a point
higher than the lizard, and then attacked from
behind. These observations are reminiscent
of the detour behavior seen when jumping
spiders hunt—discovered in the 1990s (11). It
is remarkable that Turner’s views on animal
intentionality preceded present-day explora-
tions of the same topic by a century. Even
though his experimental work was known
to contemporary giants such as John Watson
and Thorndike (4) and across the Atlantic by
later Nobel laureate Karl von Frisch, Turner’s
visionary ideas about animal intelligence did
not resonate in the field; perhaps they were
simply too far ahead of the time. Accordingly,
they are almost completely unrecognized in
the current literature.
Further highlighting the importance and
insightful nature of Turner’s work, in 1913
he reported on the effects of age and sex on
cockroaches trained to navigate mazes (12).
Turner found that individuals placed an em-
Department of Psychology, School of Biolological and
Chemical Sciences, Queen Mary University of London,
London, UK. Email:;
530 30 OCTOBER 2020 • VOL 370 ISSUE 6516
Published by AAAS
on October 29, 2020 from
phasis on either speed or accuracy: Older
cockroaches choose slowly but more pre-
cisely. Extraordinarily, Turner suggests that
the hesitation that cockroaches display when
evaluating their options bears the hallmarks
of will, a facet of consciousness. The question
of whether humans and other animals exhibit
free will continues to generate controversy
among neuroscientists and philosophers.
That insights from insect behavior could con-
tribute to this debate has only recently been
suggested again by neuroscientist Martin
Heisenberg (13), who proposed that insects
display an awareness of the consequences of
their actions and evidence of free will in de-
ciding between options.
Why is Turner not more widely credited as
a major luminary in research on animal in-
telligence? Turner faced substantial obstacles
because of his ethnicity. Despite publishing
many important papers, he was not given
a post at a major U.S. research university.
Turner’s work was thus conducted without
access to state-of-the-art laboratory facilities
or library resources. One reason for Turner’s
relative obscurity today may be that he had
no possibility of mentoring research students
who would have carried his ideas into subse-
quent generations. For comparison, Russian
Nobel laureate Ivan Pavlov (1849–1936),
famed for his studies on classical condition-
ing, trained more than 140 co-workers. One
cannot help but wonder what Turner might
have achieved if he had had comparable re-
sources and manpower. The entire field of
animal cognition may have developed dif-
ferently. Would a “cognitive revolution” have
been needed against the dominant ideas of
behaviorism that ruled psychology for the
first half of the 20th century (postulating
that learning largely happens in the form of
simple associations), if Turner’s ideas about
advanced cognition in animals had generated
a movement at the time he expressed them?
African American historian William
Du Bois (1868–1963) lamented that “C. H.
Turner, one of the great world authorities on
insects, nearly entered the faculty of Chicago
University; but the head professor who called
him died, and his successor would not have
a “N-----,” despite a reputation which was
European; Turner died in a high school of ne-
glect and overwork” [(4), p. 348]. The institu-
tion at which Turner taught from 1908 to 1922
was Sumner High School, a school for African
American children in St. Louis. During his
time there, he and his pupils would have wit-
nessed the East St. Louis massacre in 1917,
during which white mobs murdered more
than 100 African Americans; another 6000
lost their homes as a result of arson attacks
on their neighborhoods (14). Turner was ac-
tive in the U.S. civil rights movement, and
years before coming to St. Louis, he wrote
that an emphasis on high-quality education
and a conscious effort to abandon prejudices
might eliminate barriers between Blacks and
whites within a few decades (15).
One would hope that nowadays, a person
of Turner’s caliber might not face similar ad-
versity in terms of academic employment op-
portunities or long-term recognition of their
contribution to science. But even today, very
few scholars in animal cognition, or indeed
across biology, are Black. Turner clearly rec-
ognized the importance of ethnic-minority
role models from the earliest stages of educa-
tion; their near-complete absence in a field of
scholarly study will require concerted coun-
terefforts. Funded summer schools for ethnic
minority students can also make a substan-
tial difference to inspire budding scientists.
Institutions must make still-stronger efforts
to eliminate biases in hiring, promotions,
and salary decisions and to celebrate the
successes of ethnic minority scholars. Even
where they do (and there is likely plenty of
room for improvement), overt or poorly con-
cealed racism is still commonly experienced
by underrepresented ethnic groups, even in
academia. This will likely discourage many
aspiring scientists from venturing further. A
hopeful development is that some conference
organizers are taking steps in the right direc-
tion to increase inclusivity; for example, the
Animal Behavior Society annually supplies
the Charles H. Turner award that prioritizes
traditionally underrepresented groups for
conference travel funding. More than ever,
humanity needs to be inclusive to confront
current and future challenges. Diversity in-
creases the pool of talent and, as Turner’s
example shows, has the potential to trans-
form entire fields. j
1. C. H. Turner, Science 19, 16 (1892).
2. C. H. Turner, Science 20, 39 (1892).
3. C. H. Turner, Science 30, 563 (1909).
4. C. I. Abramson, Annu. Rev. Entomol. 54, 343 (20 09).
5. C. H. Turner, J. Comp. Neurol. 2, 95 (1892).
6. C. H. Turner, J. Comp. Neurol. Psychol. 17, 367 (1907).
7. N. Tinbergen, J. Comp. Physiol. A Neuroethol. Sens.
Neural Behav. Physiol. 16, 305 (1932).
8. C. H. Turner, Biol. Bull. 15, 247 (1908).
9. C. H. Turner, Psyche 19, 100 (1912).
10. C. H. Turner, Biol. Bull. 13, 333 (1907).
11. M. S. Tarsitano, R. R. Jackson, Behaviour131, 65 (1994).
12. C. H. Turner, Biol. Bull. 25, 348 (1913 ).
13. M. Heisenberg, Nature 459, 164 (2009).
14. J. N. Harrington, Buzzing with Questions: The Inquisitive
Mind of Charles Henry Turner (Boyds Mills Press, 2019).
15. C. H. Turner, in Twentieth Century Negro Literature (J. L.
Nichols, 1902), pp. 162–166.
End of
Civil War
B.Sc., University of
Cincinnati; publishes
on comparative
anatomy of bird brains
M.Sc., University of
Cincinnati; publishes on
individual variation and
intelligence in spiders
spatial learning in
a bee by moving
landmark at nest
in a snake
E. St. Louis
massacre while
Turner teaches at
school in St. Louis
Turner dies
in Chicago
Tinbergen publishes his
“pine cone” experiment on
spatial learning in wasps
Tarsitano and
Jackson discover
detour behavior
in a spider
discusses “free
will” in insects
Ph.D., University of
Chicago; publishes
individual learning
curves of ants
Turner is born
in Cincinnati
Maze learning
in cockroach;
discusses a
“will” in roaches
From Charles H. Turner to
comparative cognition: 1850–2020
Charles H. Turner made important observations about animal cognition, which went
against the leading paradigms of the time. His ideas have stood the test of history, but
Turner’s work has largely been forgotten, likely because his ethnicity prevented him
from becoming a research team leader and so he could not train scientists who might
have continued his approach. Turner was active in the U.S. civil rights movement and
advocated that education is key to overcoming ethnic barriers in society.
30 OCTOBER 2020 • VOL 370 ISSUE 6516 531
Published by AAAS
on October 29, 2020 from
Charles H. Turner, pioneer in animal cognition
Hiruni Samadi Galpayage Dona and Lars Chittka
DOI: 10.1126/science.abd8754
(6516), 530-531.370Science
This article cites 13 articles, 1 of which you can access for free
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Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of
on October 29, 2020 from
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Social movements in several countries are stimulating a reconsideration of academic structures and historic figures and promoting reparation and recognition of marginalized and forgotten black scientists. A paradigmatic case in that sense is Charles Henry Turner (1867–1923) who was the first African American to receive a graduate degree at the University of Cincinnati and one of the first in earning a PhD degree of the University of Chicago. He performed numerous experiments on sensory perception, orientation, and mating of solitary and social bees, most of which have been unjustly forgotten despite the fact that they anticipated fundamental concepts of animal cognition. We review these studies and highlight the importance of his ideas for modern views of animal cognition and the study of bee behavior. We conclude that besides his scientific contributions, Turner is an inspiration for scientists fighting against social adversity and prejudices.
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Charles Henry Turner was an African American scientist who, while eking out a living as a high school science teacher, made important advances in the study of insect learning and behavior. Contributions include the development of research methods, investigations of color vision and pattern vision in honey bees, and the first demonstration of Pavlovian conditioning in an insect. This review begins with a biography and continues with a summary of his major research accomplishments. Also included are quotations from his publications and from people who knew him. In addition, the question is raised as to why Turner did not receive an academic appointment, and similar data of racial disparity are presented on the small number of African American entomologists. It is suggested that the story of Turner can be used to increase interest in entomology, especially among African Americans.
The terms "reversed-route detours' and "forward-route detours' are introduced to distinguish between detours that require moving away from a goal and those that do not. The first evidence under controlled laboratory conditions is provided that salticids can perform reversed-route detours. Two species were tested: 1) Portia fimbriata, a web-invading salticid from Queensland, Australia, that normally preys on web-building spiders; 2) Trite planiceps, an insectivorous cursorial salticid from New Zealand. Although both of these species completed reversed-route detours, T. planiceps was much more dependent on prey movement than P. fimbriata. Interspecific differences appear to be related to the different predatory styles of these two salticids. -Authors
"Reprinted from the Journal of comparative Neurology and Psychology, Vol. XVII, No. 5, 1907." Thesis (Ph. D.)--University of Chicago. "Literature cited": p. 425-426. Replace;
Scientists and philosophers are using new discoveries in neuroscience to question the idea of free will. They are misguided, says Martin Heisenberg. Examining animal behaviour shows how our actions can be free.
  • C H Turner
C. H. Turner, Science 30, 563 (1909).