State Vs Event Behaviours
From Jill MacKay on May 18th, 2017
Students often ask questions about the difference between an event behaviour and a state behaviour in ethology. In this short video we’ll go over some of the basics – remember Martin and Bateson’s Measuring Behaviour is an excellent resource for more information.
Martin & Bateson said that events and states lie at opposite ends of a continuum. This is a good way to think about it.
Think of this arrow as the amount of time you’re planning to watch the animal for.
Events are the small behaviours that happen during this time. It’s hard to count how long an event lasts for because it’s such a tiny fraction of the overall time you spend observing the animal. Instead we count how many events occur in a given period.
By contrast, states are bigger behaviours that happen in this period. We could count how many states occur, but there might only be one state, or very few states observed. Instead of counting how many states we see, it makes more sense to count how long those states last for. We can then talk about how long an animal spent in a particular state for that given period.
Some states can be what we call ‘mutually exclusive’. For example when this cat is lying down, she cannot be standing up or sitting or in locomotion. The lying behaviour is mutually exclusive. Most often we think about postural behaviours as being mutually exclusive, but there can be others, for example fighting and allogrooming. We often use modifiers in our ethogram, for example here we might be interested in state behaviours, but interested in what the tail is doing as a modifier.
In this ethogram, lying and standing are mutually exclusive states, but tail swishing is a state that could be occurring during either a lying or standing bout.
When creating your ethogram you’ll decide whether behaviours are states or events, but when you pilot your data collection and use your ethogram for the first time, you might decide to change a behaviour from a state to an event, or vice versa, depending on the practical considerations of data collection. It all depends on how you’re recording that data.