The Twinstitue on BBC2 usefully demonstrates some of the strengths and limitations of ‘laboratory’ experiments.
The series subjects a number of twins to various experiments in order to try and isolate the effect of one variable on another.
For example in one experiment in a recent episode, the twins were split into two groups and made to sit an IQ test, under identitical conditions, except that group A had their phones taken away, while group B were asked to place their phones on the desk.
The point of the experiment was to measure how the mere presence of a mobile phone affected performance in the IQ test – given that everything else was controlled for (both the environmental conditions and presumably the twins having similar intelligence levels because of their similar genetics and social backgrounds) this seems to be an effective way of isolating one variable, in this case, the presence of a mobile phone.
The results were quite stark – the group with the phones on the desk got significantly lower test scores than the group who had their phones taken away, which supports similar findings of other experiments which also suggested that the mere presence of a phone can be distracting, and hence means you are less able to focus on a particular task, such as doing a n IQ test.
In another (not so robust) experiment, two pairs of twins are subject to a sleep deprivation experiment in which all the twins have to stay awake for 30 hours, but one pair ‘sleep bank’ before the 30 hours, getting an extra 4 hours of sleep a night (4*1 hours for for days previous), while the other pair are allowed to nap for 12* 20 minutes during the 30 hours.
The twins are tested on reaction times before and during the experiment – everyone does worse after the 30 hours, but the ‘sleep bankers’ perform much better, which was quite surprising.
The limitations of the above experiments
While the first experiment seems to be reasonably valid, in that it’s tightly focused, and quite narrow, and has several participants, the second seems much weaker – only 2 pairs is hardly representative, but with such a long experiment and such extensive testing, one can see how to increase the numbers would get expensive very quickly, given that every respondent needs monitoring for 30 hours.
Also with the second, I would have liked to have seen a control group – another twin pair who just went for the 3o hours sleep with no banking or napping.
We don’t tend to use experiments in sociology very much, but this series touches on experiments which are of sociological relevance, so it’s very much worth a watch!