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Posted by on Jul 23, 2013 in Miscellany, Politics, Skepticism | 4 comments

Arbitrary yet potentially principled: ages of consent

The recent case of a South African film (Jahmil X.T. Qubeka’s “Of Good Report”) that was refused classification by our Film & Publication Board (FPB) raised the debate of whether age restrictions were justified or not. You can read more about the particular case on Daily Maverick or Africa is a country if you like, while I’ll move on to discussing the general issue of age restrictions in domains such as drinking, driving, voting and of course sex.

It is of course true that any particular age of consent for sex is largely arbitrary, just as age limits on driving or drinking are. We won’t be able to find a clear line between 15 and 16 year-olds that consistently demarcates maturity from immaturity (let alone find a clear definition of ‘maturity’). However, there’s also no efficient – and also principled – way to draw these sorts of lines without imposing an arbitrary age. In a future world where we can track capacity for factors like reason and consent in real-time, per individual, we’d perhaps not need these arbitrary limits, and particularly co-ordinated, willing and fearless 13 year-olds could get emancipated and go fight wars if they like.

But in the meanwhile, we need to work on expected or probable capacity to perform the function in question, whether it be drinking, driving, voting or consenting to sex. An age of consent, for example, makes it easier to prosecute sex offenders on the assumption that in general, people either aren’t consenting, or aren’t sure what they are consenting to (so, not consenting) below the age stipulated.

While we can get these various ages wrong, and various jurisdictions disagree on where to set them (or so do inconsistently), I can’t see any merit in the suggestion that these sorts of decisions should be delegated to the family (because they are supposedly better placed to know the child’s capacities), rather than left to the state. In fact, I find the suggestion even less principled than a state-imposed limit, because we have no reason to trust the family’s entirely subjective judgement in these matters more than we should trust the aggregate gaze that a state could apply. I’m not sure I should be allowed to put my (hypothetical) 12 year-old to work doing deliveries by car, for example – my incentive to make money could lead me to overconfidence in her driving abilities.

So, the precise age we set is always going to be arbitrary, because there is no age that guarantees “full” maturity or competence. But we’re not aiming for that – what we’re aiming for is “adequate” maturity or competence, such that we limit as little freedom as possible while also protecting the largest proportion of various vulnerable populations that we can. And here’s the thing: it is possible to triangulate on the appropriate age in general, even if individuals might not fit the norm. But as I’ve previously argued, the exceptional cases should not be the basis for policy:

laws or insurance premiums can’t be tailored to individuals. As much as we are individuals to ourselves, interventions intended to work on aggregate have to treat us as belonging to a category – and the question then becomes how those categories are defined. And here, we need to start thinking about the least wrong way of doing this, and perhaps being more willing to tolerate principled ways of treating us simply as a number.

If we can find the approximately appropriate age, then we know that we’d be making fewer mistakes (in terms of restricting freedom) the closer someone is to that age, and doing more good (in terms of protecting more people from harm) the further away (younger) someone is from that age. If we know that in general, consent is likely to be absent, we’re taking pragmatic steps to protect people from harm rather than imposing a moral standard when we say that it’s illegal to have sex with a 15 year-old.

So while we can debate what an appropriate age is, I don’t see room for discarding the concept of establishing and maintaining a guideline. And, as for how to set these guidelines in the least arbitrary way possible, we do have relevant knowledge. It would be a simple matter to track road accidents, for example, and do some analysis of factors like the age of drivers, and their levels of intoxication. (One might even suggest that insurance companies have cottoned on to these arcana.)

If it turns out that 16 year-old drivers look to be as safe as 20 year-old drivers, we know that we should either a) let 16 year-olds apply for licensing or b) not let 20 year-olds do so. And if a blood alcohol level of X gives you the same risk profile as a level of 0, we know that X is safe, etc. The fact that states might take shortcuts in figuring this stuff out and making the laws doesn’t mean there aren’t sound principles by which to do so, if we had the time and desire to.

Then, more generally – we know that it’s only at age 25 or so (for men) and 23 or so (for women) that the prefrontal cortex (PFC) reaches maturity. The PFC is the last part of the brain to develop, and (unfortunately for parents) is the part of the brain that governs impulse control, risk-seeking/aversion, and that encourages hyperbolic discounting (in short, we need a developed PFC to balance short-term rewards against long term goals). Putting that together, what we have is a brain that conduces to driving too fast, on too many drugs or too much booze, to get to a place where you’ll enjoy lots of sex with too many strangers and too few condoms.

In other words, it wouldn’t be at all arbitrary to say that 24 (to pick the mid-point) would be an efficient and justified way to limit all sorts of activities. But asking people to wait a third of their lives before driving or having a drink seems excessive, so we pick a younger age (exactly how young can vary, depending on the severity of risk in question) where most people are likely to be competent, even if some mistakes will be made. It’s a question of pragmatism, not of morality.