Lauren here!
Here's an interesting idea:
Do you think you can tell a person's personality by playing them?
For the opening, e4 is more of an aggresive and more tactical opening.

Maybe these people are more of a risk taker personality?
For me, I am an e4 player because I like to attack.

d4 is more conservative. Maybe they just want to keep life simple as possible.
If your oppenent are into gambits, they aren't afraid about risks because they are sacrificing material
for development. The most risk taking gambit is the "Danish Gambit", where you sac two or three pawns for deadly development of the two bishopson the long diagonals.
Personally for me, I'm not into gambits because I don't like taking that risk of sacrificing pawns.
You just need to know what works for you and that takes time...

What do you think?

Barbara here!

I agree with Lauren. In chess, tactics are short-term plans.
Positionally are long term plans. Probably with a
person who plays positionally (opens up with d4, c4) have more long term plans
than people who play tactically. Positionally players are usually more comfortable of what they're doing
in general because of they are sure of themselves.
For me, I am a positionally player and likes to open up with c4.

It takes time to figure out what opening(s) works for you. The most important thing is to be comfortable playing it and of course, have fun.