[mfukar]

  Any control group on the babies to see if it's actually fear of spiders they learnt, or just fear?

What would comprise the control group? Psychopath baby crickets?

[streety]

I'm not sure what the cricket equivalent would be but in a mouse model open space and bright space anxiety tests would be a reasonable approach to understanding whether the anxiety is general or specific to spiders.

[nervechannel]

Exactly. Something else scary that doesn't resemble a spider.