Hold on a minute.
Specifically talking about life, currently we only do that when there is an irreversible pathology (excluding the death penalty). That's what my previous post explained, which you responded to with:
Which I took to mean as that we currently protect children without an extreme pathology that affects certain areas of their brain in law. Was that not what you meant?
No. What I was saying is that we institute a cognitive threshold with children. We offer additional rights to brains that are additionally developed.
A 1-year-old has a right to life, but not a right to make their own medical decisions, own property, own a gun, vote, drink alcohol, drive a car, get married, work, view pornography. Etc.
A 16-year-old has a right to life, can under certain circumstances get married, drive a car, and in rare circumstances make their own medical decisions and own property, but cannot own a gun, vote, drink alcohol, work certain hours or jobs, and view pornography.
A 21-year old still can't run for president.
An 18-year-old felon can't vote (at least for a time).
An 18-year-old who has committed a crime can have their freedom of movement taken away. But this is restored after a time period under the premise that this time period will somehow fix whatever was wrong with their brain and they'll be able to function again.
An 18-year-old who has committed the specific crimes of pedophilia or drunk driving may have certain rights taken away even while generally released. For example, tracking or vehicle restrictions.
An 18-year-old who has committed other specific crimes may lose their right to life.
In some states, at some ages, under the right conditions, your right to suicide is recognized.
In some states, at some ages, under the right conditions, your right to take certain drugs is recognized.
For all of the above, a lack of mental health (other than the criminal lack of mental health) also can result in a reduction of corresponding rights.
The point here is that brain development is the key to obtaining rights in society. Our entire structure of rights is centered around cognitive capability. Whether you're an adult, a child, an infant, none of it is particularly germane to whether you have rights. What matters is whether your brain can be presumed to function well enough to function reciprocally. Specifically, does your brain enable you to recognize that other people have the same rights and expectations that you do, and enables you to treat them according to this reciprocity. If it does not, we logically do not confer those same rights to you.