What gender are these two chicks?

[The Chickadoodles]

I have 1 Rhode Island Red and 1 Australorp chick. The Rhode Island Red is giving me vibes of a rooster because both of them are 3 weeks old but the Rhode Island Red has smaller wings and less feathers than the Australorp. The Rhode Island Red sometimes makes itself bigger in front of the Australorp and an older female chick. The Australorp has longer wings and more feathers. Is there any difference?

Here are some pictures: The Australorp is the black one and the Rhode Island Red is the brown one if you don't know.

 

[21hens-incharge]

Apples and oranges really.

Different breeds will feather at different rates.

 

[Stacyoung13]

The australorp loos like a cockerel with that comb, the rir looks to be a Pullet.