Natural selection favors altruistic acts when the resulting benefit to the beneficiary, corrected for relatedness, exceeds the cost to the altruist.
The effects of kin selection are larger than the effects of direct natural selection on individuals.
Altruism is always reciprocal.
Natural selection does not favor altruistic behavior that causes the death of the altruist.
Natural selection is more likely to favor altruistic behavior that benefits an offspring than altruistic behavior that benefits a sibling.
Never occurs in natural populations
Is expected when the species as a whole benefits from it
Occurs only when closely related individuals benefit from it
Is expected when it increases the long-term inclusive fitness of the altruists
Is expected when there are plentiful resources to share
It immediately benefits both the performer and another individual.
It immediately benefits another individual at some cost to the performer.
It immediately benefits the performer and imposes a cost on another individual.
It imposes a cost on the performer and the other individual.
It imposes a cost on the performer without benefiting another individual.
The same as the coefficient of relatedness between mother and daughter
Less than the coefficient of relatedness between father and son
One sibling and three nephews
Seven first cousins
The coefficient of relatedness