Parallels between sperm whale clans and human societies can help us as we think about, and try to study, both sperm whales and humans. The extraordinary picture of human social evolution that archaeologists, anthropologists, and historians have built up over more than a century of study can indicate not only the patterns we might find in sperm whale clans but also how variable those patterns might be.

Mother and Baby sperm whales - Photograph Source: Gabriel
Barathieu –
CC BY-SA 2.0
The sperm whale is extreme. They have the largest brains and the
largest noses on Earth. The sperm whale’s nose is a huge and
sophisticated sonar device that produces the most powerful sounds of
any animal––and we’re only just starting to understand their
communication methods and the spectacular complexity of their modes
of life.
The facts about sperm whales rival in some ways the extreme
capacities and behaviors that until recently we thought were
uniquely human.
The sperm whale, for example, has the greatest geographical division
between the sexes: The females live in tropical and subtropical
waters all around the world, while the mature males, reaching three
times the mass of the females, are mostly found in or near the
Arctic or Antarctic. Sperm whales, particularly the females and
young, are extremely social. They live in permanent family units of
about 10 animals who move together over huge swaths of ocean. The
females and young males babysit the infants while mothers make dives
of 40 minutes to depths of up to a kilometer to catch the deep-water
squid, which is their staple food. Females also suckle each others’
infants, and families defend themselves against predators
communally. The family units form groups with others, but only limit
creating these groups with other families in the area.
In 2002, fellow scientist Luke Rendell and I made our big discovery
as we looked at the different dialects of the sperm whale family
units that we had been studying off the Galápagos Islands. The sperm
whales do much of their communication using patterns of clicks
called codas. We noticed that nearly all the families made codas
with one or other of two motifs: Regular codas such as
“click-click-click-click-click,” or Plus-one codas,
“click-click-click-[pause]-click.” They were consistent: the Regular
families nearly always made regular codas. The Plus-one families
similarly stuck to making their codas. And, although both types of
families can be found in the Galápagos waters and formed groups with
other families, we had never seen them group with each other. We
called the collections of families with the same repertoire, clans.
The clans differ by more than patterns of clicks and grouping
choices. They also tend to travel through the ocean differently. As
we followed groups of sperm whales around the Galápagos Islands in
our boat, those groups made up of Regular families wiggled this way
and that, while groups of the Plus-one clan typically travelled in
straight lines, making them much easier to follow. Groups of the
Regular clan tended to all dive together, while the Plus-one groups
staggered their dives, a cultural adaption that may provide for
better babysitting. There is no sign of difference between clans in
the nuclear genes that might code for behavior, so the differences
between the clans comes down to culture. A young sperm whale learns
the culture of her clan from her mother and the other females in her
family and clan.
Following the discovery of different clans off the Galápagos, pairs
of clans were also discovered in the waters off Chile, Japan,
Mauritius, Brazil and in the Caribbean. A 2022 study of sperm whale
codasright across the Pacific found seven clans. One, the Short
clan, was recorded in parts of the worldranging from Japan to Chile
and from British Columbia to New Zealand. In contrast, the Plus-one
was only recorded from our studies off the Galápagos and nearby
waters off mainland Ecuador.
The clans have an average of about 20,000 members. These whales can
tell, from dialects and other behavior, that they are clan mates. As
far as I can tell, the most comparable large-scale societies are
those of humans, our ethnicities and nations; each having their
distinctive dialects, distinctive behavior, and social barriers.
There are other parallels. Like nations, clans vary greatly in
size—the Short clan likely has many more members than the Plus-one
clan.
The clans in the Atlantic seem structured rather differently from
those in the Pacific, with smaller ranges, less extensive movements,
and different forms of dialect distinction.
Somewhat similarly, prehistoric and historic ethnicity and language
varied considerably between humans on different continents. One of
the most striking parallels between sperm whale clans and humans is
symbolic marking. We use cultural artifacts, such as dialects,
clothing, and art to symbolize our groups, and sometimes
deliberately modify these symbols to distinguish groups. Different
sports teams from the same city typically use contrasting colors.
Previously, it was assumed that such symbolic marking was unique to
humans. But the codas of sperm whale clans from the Pacific are more
different if the clans overlap than if their core ranges are in
different parts of the ocean.
These parallels between sperm whale clans and human societies can
help us as we think about, and try to study, both sperm whales and
humans. The extraordinary picture of human social evolution that
archaeologists, anthropologists, and historians have built up over
more than a century of study can indicate not only the patterns we
might find in sperm whale clans but also how variable those patterns
might be.
The parallels between these two unrelated species living in quite
different environments suggest common environmental drivers for
large-scale social structures.
This suggests that our ethnicities and nations, as well as sperm
whale clans, may have risen due to large brains, cooperative care of
the young, wide-scale movements, or the capacity for culture. In
contrast, attributes that are unique to humans such as fire and
complex tools, and those that are unique to sperm whales, like the
eating of deep-water squid, seem less likely to be important.
These discoveries and parallels help emphasize the need to protect
sperm whales. The global population is heavily reduced by massive
whaling and is struggling to survive in the face of new threats,
including plastic pollution, fishing gear, and ocean noise. For the
sperm whale clans to survive, human groups need to change our
behavior.
Hal Whitehead has been studying sperm whales for 40 years, tracking their groups at sea from a 40-foot sailing boat and trying to understand their social and cultural lives. He is a professor at Dalhousie University in Canada.