Making computer models that ensure justice prevails

‘I often jokingly say that I'm trying to do the same thing kids do. As early as two or three years of age, children start picking up the rules of causal relationships by listening to adults. A child might say to another child, “I want to play with you because you're my friend.” But how exactly did they learn this, as a child? I study people's perceptions of causal relationships, with the goal of creating a logical framework for them.’

So where does Dean get his data, by eavesdropping in schoolyards? ‘I do know of colleagues whose research deals with children, and they’re finding some really interesting examples. But I'm no childhood language expert – give me a legal document any day.’ 

Dean relies heavily on court cases for his research and models. ‘These are a conventional source of very precise information that can be easily accessed: did the patient die as a result of negligence on the doctor's part, or because of their own poor diet? When the trans woman was fired from her job, was there discrimination at play? Every aspect has been recorded and includes clear supporting arguments.’

Life’s work

Semantics are extremely important in court cases. A small word like ‘because’ can have drastic implications. ‘In a discussion, people will sometimes say, “It's just semantics”, by which they are implying that something is meaningless. But I've dedicated my whole life to it.’

‘Courtroom trials often deal with cause and effect: If the cause had not been present, the subsequent effect would not have taken place either. This philosophy can be traced back to David Hume. Yet something about this isn't right. I can say, “I have an Irish passport because I was born in Dublin.” But even if I hadn't been born in Dublin, there are still other places in Ireland that would make me eligible for an Irish passport. Different cause, same effect.’

Replacing judges

While a concrete application of Dean's models could help judges render their decisions, that is not his primary goal – he is first and foremost a scientist. ‘I love looking at court cases, but in the end, I think that there's a stable concept to be found for both inside and outside the courtroom. I'm looking for that overarching concept.’ 

So is he secretly on a mission to replace judges with computers? He laughs and says, ‘No, we need judges to work out the implications of the rules. But I hope to be able to make recommendations.’ At the moment, Dean's models are not yet being used in court. ‘First, I need to make sure I get it all properly set out for my dissertation. But yes, the plan is to make judges aware of my work.’

New insights

Where does the researcher find inspiration? ‘A good researcher is a happy researcher – that's what I tell myself as an excuse to go to fantastic concerts in the Concertgebouw. Ballet and opera in the ‘Stopera’ building; when you're a student, you get a big discount on tickets. And the great thing is that new insights pop into my head while I'm there.’

About Dean McHugh

• Member of the Causal Inference Lab at the Institute for Logic, Language and Computation;
• More information on Dean's personal page on the UvA site.