> There's absolutely nothing to say what a person, even a baby, will do in a certain situation.

Perhaps not for a single individual in a single situation, but on average humans are quite predictable, and not the unique little snowflakes you make them out to be. If someone slaps you in the face, odds are you will be angry, frightened, surprised, or some combination thereof. You're probably not going to hug that person and invite them over for dinner. Of course there are 6 billion people on this earth, so there may be someone out there who will start singing when slapped, but statistically that person doesn't exist.

> We are not automata, or if we are some sort of automaton we are a type of automaton that is too complex for us to understand and predict.

Understanding the circumstances, thoughts, and emotional state of others is required for empathy. If humans were truly too complex for other humans to understand and predict, empathy could not exist. And if people were unable to predict others, it would be impossible to troll people on the internet.

> In that sense I don't see how there can even be a valid null hypothesis. We don't even know what to expect in the first place, so what are we comparing some specific observation to?

By that logic there can never by a null hypothesis for any experiment. The world is a big and complex place, and there is pretty strong evidence that randomness plays a big role at the smallest scales that we currently understand. Which direction will this rock go when I drop it? Will it even move at all? Who knows! Through the power of quantum teleportation it could suddenly appear anywhere.

> The idea is that the study has "controls", but note we're not even given the numbers of the subjects the experiment involved.

Why are you worrying about the number of subjects? If human behavior cannot be predicted at all, we wouldn't really expect to see a pattern no matter how many subjects participate in the study, would we?

> Even the bar chart on the right has percentages rather than numbers- why? Well, because it probably involved a dozen subjects or so. A couple of dozen? Probably not more than that.

If you have a couple of dozen subjects, observing something happening less than 20% of the time in one group and more than 60% of the time in the other is actually pretty significant. You don't need hundreds of subjects when the difference is that big. [This page](http://www.nature.com/nature/journal/v415/n6873/fig_tab/4157...) seems to suggest that one group had 14 participants, and the other 13. I suppose that technically qualifies as "couple of dozen".

> We're talking about tiny, tiny numbers here. There's not really enough to seriously talk about "controls". And my intuition is that if the study was done on, say, a few hundred babies, results supporting the researchers' conclusions would dissolve into thin air. But- who knows?

I'm sure researchers everywhere would absolutely love to have hundreds of people participate in all their studies. But that's expensive. Let's imagine a world where this study was done on 200 babies. People in that world would still complain about this study! Instead of "27 subjects? Surely that is too few to conclude anything!" we would hear "How dare those researchers waste a million dollars to investigate how often babies smash stuff with their head!". Imagine the study was unable to show any result, the outrage would be terrible.

> Why is that a valid hypothesis to state in the first place? It's making some assumptions about the baby's mind, specifically that it's the same kind of mind, in the same kind of context, as that of the person who stated the hypothesis. Well- that sort of assumption is something that has to be tested in the first place.

I fail to see your objection here. The hypothesis would make sense if the subjects were adults. It would also make sense for children. So at what age does it stop making sense? How young does someone have to be before we can no longer make assumptions about their mind? How would we even know without experiments such as the very one you are now criticizing? As someone who used to own a dog I think the hypothesis would even make sense not just for humans but also for some social animals.

> We can't just hand-wave that fundamental question away with a "duh, it's a human baby so".

Well if I had to choose between "the mind of a human baby functions similarly to the mind of a human adult" and "the mind of a human baby is completely alien and nothing like that of a human adult" I think Occam's razor favors the former. Regardless, your approach leads to some type of analysis paralysis: we can't perform a study without a hypothesis, and we don't have enough data to form a hypothesis.

> Social sciences have a tendency to make gigantic leaps of reasoning like that, and bridge the gap between observed behaviours with assumptions and common sense, or other social scientists' theories.

So in that respect it's a lot like the non-social sciences?

> There are so many things that is probably impossible to evern know for sure about our minds, no matter how much science we throw at them, or at the very least it will takes us generations upon generations of painstaking research to figure out-

That seems like a giant leap of reasoning of the same type that you like to criticize the social scientists for. Do you at least have a study that vaguely supports this theory?

> yet, a lot of the people who study minds and behaviour will gladly take them for granted and publish a paper taking them for granted, then others will cite that paper, build upon its baseless assumptions and add their own on top.

That sounds a lot like science works in practice.

> That's not science- that's turtles all the way down.

Well there's only so far you can build on a false theory before you notice that your data doesn't make any sense.

> I do think that's what I meant but even so- what does that tell us? Who says that's not what should be expected? We're back to forming a valid null hypothesis, and I don't see how that is established.

I suspect that is primarily because you're being deliberately obtuse because of your dislike for the social sciences.