my boys are 19 months apart both very smart but the younger one already couple months ago at 2.5 years old started surpassing his older brother at certain things (like reading). At first the older one was not happy about it. His big thing was that he wanted to teach his little brother everything and suddenly realized he couldn't. But it has given him motivation to see if he can do what his younger brother can do and he just tries harder sometimes.
For now, it's not really an issue at our house, I just try to find things when the older one can teach his younger one and feel like he's a good big brother. As he says, it's "his job to teach his brother things"
There is a chance that come Middle school, the younger one might be more grade skipped / subject accelerated than the older one and then we may run into problems but even then I'm sure we'll find a way to let them both feel good about themselves.
