Identifying Controlling Variables’

AAAAs a behaviourist I am a bit of a nerd when it comes to ‘controlling variables’, or in other words identifying what factors in any given moment made X do Y.  It is really only possible to do this if we can define the problem in a behavioural way.

Firstly we have to be able to pinpoint the precise time and situation in which a behaviour occurred. That can be hard. We like to think in terms of categories of behaviour rather than specifics. This is particularly prevalent when thinking about relationships (a series of contacts that happen over a period of time). We like to say, “Claire is friendly” rather than, “On 32 occasions when I met with Claire she exhibited signs of prosocial behaviour, specifically: smiling at me, nodding, asking questions about me and telling me interesting facts about herself”. In fact the second sentence would be a very weird way to discuss someone, and is not recommended in casual conversation.

Lets take a very common example of unwanted behaviour and describe it factually. A common complaint in relationships is, “they don’t listen to me”. We rarely mean that they don’t listen at all, as in “there have been zero instances of voice-based communication between us.” Usually a more behaviourally specific assessment is that on a number of separate occasions in response to my verbal stimulus this person has displayed behaviour indicating non-responsiveness, namely: looking out of the window, checking their mobile phone, carrying on with their activity without raising their head, making no verbal response, not initiating my request, or doing the thing I just asked them not to do.”

In order to really work out what the controlling variables are for ‘not listening’. We have to be able to pinpoint one incident in time. This is because every time the behaviour happens it will be differentially motivated, although there may be patterns that crop up over multiple examples.

For example, a teenager not listening to his mum one Tuesday morning as he is just about to leave for school. She is in the kitchen and hearing him come down the stairs calls out “don’t forget your lunch box”.  He simply ignores her and by-passes the kitchen, leaving without it.

This may have a number of possible controlling variables:

  1. He did not actually hear because he was distracted by either an internal stimulus (thinking about the girl he met last night) or an external one (his phone was ringing).
  2. He dislikes the lunch so does not wish to take it.
  3. He likes the lunch, but in the moment he hears his mother’s prompt to fetch it, he is already committed to his route through the door, and does not wish to detour for the lunchbox. In two competing demands, (1. get the box, or 2. get out of the door asap) people often satisfy their immediate priority over a later one. It is true, that when he gets to the time in which he would like to eat the lunch he might regret not detouring for it. But that motivation will not kick in until later in the day.
  4. He is worried about his weight and so wants to ‘forget’ the lunchbox.
  5. Having two competing demands (get out of the door, fetch the box) is actually anxiety provoking because there is a time pressure. In this case he may not be actively choosing to ignore his mum, rather the anxiety is saying to him “Overload, overload”. This may well be the case if he also has other preoccupations (worrying about school, or an argument with peers).  it is possible he just keeps moving in the direction of travel, simply because it requires less decision-making.
  6. He has had a row with mum, and to get the box will mean having to face her in the kitchen. He would rather not, so avoids the kitchen.
  7. Getting the box has an inadvertent ‘cost’. Many teenagers report that parents seize on any face-to-face meetings to add little interrogations, e.g. “are you coming straight home after school? Did you finish your maths homework?” Parents report that teenagers are often ONLY available for these brief snippets of interaction at ‘feeding points’. Therefore the teen becomes wary of food-related invitations.
  8. He does not want to carry the box (it’s an extra thing to lug around, his hands are already full, it leaks, he would have to take it to PE first lesson etc.) This is particularly likely if he has learned over time that forgetting the box means mum brings it to school for him and leaves it at reception. In that case she has inadvertently rewarded ‘forgetting’.
  9. The girl last night ignored him and he now wishes to be in the position of ignorer rather than ignoree. He has a vague and newly-formed notion that women are the source of all pain.
  10. He is happily secure in the knowledge that no bad things will happen to him, lunch or no lunch and simply does not see this as enough of a priority to detour for the box. In the past when he has forgotten lunch he and his mates have visited the shop near school, or people have shared their lunch with him. It has been fine. There are few rewards for making that detour.
  11. There is something else or someone else in the kitchen he wants to avoid
  12. His friends are waiting for him, and peer factors are more important.
  13. He had already put his earphones in.

These are just a few of the possibilities, and there are another myriad of variables affecting Mum’s emotional response. If things are fine in other ways she might laugh off this one incident. If however it comes after a long line of similar ‘ignoring’ situations this low-key event could act as a straw that broke the camel’s back. If she has other distractions she might not even notice. Whereas if other adverse factors are stacking up in her life this could become a battle-ground. If she spent ages making his lunch she might be annoyed, if she has noticed he’s generally off his food, she could be worried. If she thinks, shouldn’t let a good lunch go to waste, I shall eat that myself, she might experience no adverse consequences at all. People, situations, responses, they are all complicated.

Being able to pinpoint a behaviour and look at it in more detail is an example of being mindful. Mindfulness is characterised by one-thing-in-the-moment, and helps us understand that even if we can identify an important factor on one day, the same behaviour even one day later might have come about for a different reason.

So why might we want to do this in-depth assessment at all? Well, knowing some of the possible drivers and obstacles points us in the direction of solutions. We can hypothesise and then try out those solutions, to see if the behaviour goes up or down. Should mum stop taking his lunch to school and see if that makes him more responsive to her prompts? Should she tackle him about his weight? Should she stand between him and the door and hold out the box? Should she absent herself entirely from his morning routine?

A behavioural assessment can also help us to avoid interpreting the behaviour. Often our interpretations are based on the effect the behaviour has on us. So instead of looking for other drivers we assume that the consequence we experienced was the intended consequence – e.g. “I was really annoyed when he ignored me, therefore he must have done that expressly to cause me annoyance.” Whilst it is possible to be correct in our interpretations, a lot of the time they just muddy the waters.


The example above is a very simple one explaining the concept of being behaviourally specific, and then brainstorming controlling variables. This same procedure is applied to more complex behaviour in a clinical context. All behaviours are understandable at some level, we just have to be prepared to view them as a puzzle, and not stop at our first assumption. Moreover we need to look for what we might have missed out, are there other factors that could be contributing to this behaviour?

Lastly we need to understand that even when something is motivating our behaviour, we might not be aware of that. This teenager might not want to be interrogated by his mum about his after-school plans, but that thought might not have formulated clearly in his mind. Instead he might just experience this as a vague notion of not wanting to visit the kitchen at that moment. Just in the same way that you sometimes feel uneasy in a certain situation and only later realise it reminded you of a past unpleasant experience.

Next time you find yourself labelling categories of behaviour see if you can tie it down to one instance, and work out as many of the potential controlling variables as you can. The process can be remarkably illuminating.



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