Thinking Skills: Critical Thinking and Problem Solving

166 Unit 4 Applied critical thinking

DOC D

The larger a primate’s group size, the longer

they spend grooming to cement bonds

20

15

10

5

0

1306090120 150

Group size

Time spent grooming (percentage)

The four documents above – two textual and

two graphical – are typical of those used for

critical thinking questions in many

examinations. Once you are familiar with the

content, have a go at answering the questions

below, each of which is followed by a short

commentary, discussing the question and

suggesting a suitable answer (or answers).

1    In the paragraph marked Doc A, what

viewpoint is the author challenging, and

on what basic grounds does he make the

challenge?

Activity

Commentary

This is a very straightforward question. In

Doc A the author sets out his target for what

follows: the view that social networks are

distinctly human. He challenges this view by

claiming that social networks occur wherever

there are ‘bonded’ groups, defining bonding

as gathering together for more than just

physical reasons such as food and security.

This is the key difference between a social

gathering and a mere herd or pack. According

to Professor Dunbar, these bonded groups

occur among many animals, including all the

primates – apes, monkeys, humans, etc. – and

some other mammals too.

You are not asked to assess the evidence,

nor to evaluate the argument. To do that you

would need to have read more widely. But it is

clear that if the author is right in saying that

primates form groups that are bonded by

relationships, rather than mere environmental

factors, then there are grounds for the claim

that social groups are not distinctly human.

2    Does the data in Doc C support the view

that a species’ average group size tells

us something about how ‘smart’ (i.e.

intelligent) it is?

Activity

Commentary

We will begin by saying something about the

data itself. Doc C is a scatter graph. Scatter

graphs are intended to show correlations. Here

the correlation being investigated is between

brain size (the horizontal axis) and average

group size (the vertical axis) in primates. ‘Brain

size’, as explained in the notes, is a shorthand

for something rather more complicated,

namely the amount of an animal’s brain that is

associated with higher levels of intelligence. It

is measured as a ratio, and obtained by

dividing the volume of the whole brain by the

volume of the neocortex. In humans the

neocortex is over four times the volume of the

rest of the brain, making the human brain the

‘biggest’ in the defined sense.

You may have noticed the somewhat

unusual scale that has been used on the graph,

especially on the vertical axis. The lowest band

shows group sizes between 1 and 10, the

second between 10 and 100. Mathematicians

among you will recognise this as a logarithmic

scale. It is a useful device when the range of