Truth to birth order?

I’m legit worried about my second born. I have two boys, ages 7 and 3. My eldest makes me swell up with pride. He’s intelligent, diligent, athletic, sociable, and just so sweet. I thought I had it figured out.

As for my second, he’s a cool kid. He’s daring, extremely extroverted, and can read social dynamics well. He’s also able to listen and understand every conversation going on. He just gets it. However, his FN crazy! Stubborn as hell. Just wants to have fun all the time. Hard to settle. Fights chores (appropriate for his age) and anything else he doesn’t feel is fun, like eating at the dinner table or brushing his teeth. I have anxiety if I have to take him to the store. He just wants to do what he wants to do and it’s not appropriate for the situation (run and scream but all in the name of fun).

Anyway, I’ve heard this a birth order thing and the second one is somewhat like a wild card. For those with older kids, is this true? How is your second born or wild child toddler now?

I don’t know why I’m worried but I’m worried. I worry that I’m at fault as I have spent less time with my second. (The Pandemic gave me extra time with my first and splitting time between two is difficult.) Is he being neglected? I’d love some advice on how I should navigate this.