The portia genus are incredibly smart. I believe it is because its vision system, comparing to other spiders. Watch some videos on youtube and it chills how calculated the hunt is.
They seem to be in a class entirely unto themselves. There is something about the way they move and observe the world that gives them an apparent intellect beyond any other 'bug' I've seen. I used to keep bees and they are amazing in both their individual and collective ability, but it's hard to interact with them. Portia and other in the Salticidae family are almost like little dogs or something. They watch you, seem to make eye contact even, and generally are tolerant of handling and attention. Really cool little critters.
Predictably, the BBC and David Attenborough have some amazing videos about them:
Huh, interesting. That "Hunting of a spider" clip almost follows part of the intro sections in Children of Time 1-to-1. Feels like someone took 'inspiration' in someone else's homework. I wonder if it was BBC or Adrian Tchaikovsky who came first.