Speak for yourself. Most people grow up eventually.
I speak for all of us.
There is nothing "immature" or "juvenile" or "not grown up" about admitting that each of us is inherently and instinctively "racist".
It's more a matter of coming to grips with the truth that such instincts exist and that the rational mind of goodwill can (and should) do what can be done to overcome it.
Blacks are more interested-in and more vested-in the welfare of the Black population.
Hispanics are more interested-in and more vested-in the welfare of the Hispanic population.
Asians are more interested-in and more vested-in the welfare of the Asian population.
Whites are more interested-in and more vested-in the welfare of the White population.
Deny such truth at your own very great political peril and at the price of becoming self-delusional.
Such a truth does not preclude any given group from ALSO manifesting considerable goodwill and positive hopes for the welfare of others.
It's just that each of us ( as racial / ethnic / demographic groups ) tend to "take care of our own" first and worry about others second, when we can spare the energy for them.
Grown-ups tend to develop and manifest goodwill and positive hopes for those who do not look like them but individual experiences end-up governing the extent of that.
Being more concerned over the welfare of your own racial-ethnic group makes you (and me and everyone else) racist.. but instincts need not control our common public life.
You may not LIKE the label "racist" because it has so many negative connotations in our present age but it's both linguistically and practidally accurate.
There are, indeed, exceptions, however...
The vast majority of us need look no further than the skin color of our spouses and children or the racial composition of our neighborhoods to know the truth of this.
You can throw rocks and deny all you like but that doesn't validate your stance.