The Boy and the Traffic Lights
The aim of this session is to get the children to consider the conditions under which a causal connection can be said to be the case.
Describe a scenario where a boy (or girl) is staring at some traffic lights and when they ask him what he is doing he says that he able to change traffic lights just by staring at them. He says he can prove it and he goes on to stare at the traffic lights and they do change. You could even say that you have tried it and it does seem to work. Every time you have stared at traffic lights they do change.
Task Question: Is it true or false that the boy (or you, or them) can change traffic lights just by staring at them?
A more advanced scenario that was actually described by a boy in Year 5 is as follows and makes for an excellent extension activity to the above scenario:
Describe (and draw) a situation where the boy is staring at the lights but the lights have a hidden camera which is connected to a room with a man in it. The boy knows nothing of the camera or the man. The man will change the lights if and only if the boy is staring at them.
Task Question: Is the boy changing the traffic lights?
- What is a cause?
- How many causes does one thing (such as lighting a match) have?
- Could something happen without a cause (or, without something making it happen)?
Imagine someone lights a match (tell the children that they must never light a match without an adult present). Ask them what caused the match to light?