4.6 Critical thinking and science 169
interacting with the wider group, as humans
do. That would account for the concentration
of grooming on small numbers of partners. If
this is the right explanation, it would also
support Dunbar’s claim that social groups are
not a purely human phenomenon.Summary
• Scientists make observations and use
them both to construct and to test their
theories.
• Critical thinking has much in common with
scientific thinking.only correct one. The clue is in human
behaviour, and is discussed in the second
paragraph of Doc B. Humans form large
groups, compared with most if not all other
primates – 150 on average (Doc C). Humans,
as we know, use physical grooming only in
very intimate relationships. With less intimate
acquaintances, Dunbar argues, grooming
takes more varied and more acceptable forms
such as laughing, singing and gossiping. The
explanation we are looking for may therefore
be that other more advanced primates, with
larger group sizes, and with brain sizes
approaching those of humans, also reserve
grooming for their most intimate partners.
Perhaps they too have other ways of
2 Find out more about the research of Robin
Dunbar. Identify one of his theories and
one or two items of evidence he gives in
support of it.1 Is there enough evidence in the extract you
have read to conclude that some animals
form social groups similar to those of
humans? Write a short reasoned case to
support your answer.
Questions in this form occur regularly in
Cambridge Thinking Skills Paper 2.End-of-chapter assignments