That’s why scientists ( I assume they’re supposed to be the right hand side) claiming to measure “intelligence” should pick a more specific term for what they’re measuring.
If they use the word “intelligence” I’d be extremely suspicious about why they’ve chosen that word. I would assume they have a decent understanding of how the word is likely be interpreted by the other 97.5%, if not they need to get out and do some fieldwork.
Permanent? dont have that busbar flapping arund in the breeze, clip it down. Does that loopy bit have a purpose?
You just need more practice. Reheat some of those, let the iron linger, add more solder maybe flux too. until the solder flows and goes shiny.
The iron needs to dwell long enough to get both parts up to temperature so that the solder flows between both. This means that when heating a larger thermal mass, like the big wires, you need to dwell longer.
You’re heating the parts to be joined, not the solder. Add more flux.
Practice on different sized wires or parts attqached to large ground planes and so on til you get a feel for the thermal mass of the joints.
bigclivedotcom on youtube has some videos on soldering basics. https://www.youtube.com/watch?v=aIab66EgfHM