In respect to insurance issued upon the life of any minor, regardless of the age of the minor at the date of the issuance of said insurance, for the benefit of such minor, or for the benefit of the father, mother, husband, wife, child, brother, or sister of such minor, the insured is not, by reason only of such minority, incompetent to contract for such insurance, or for the surrender of such insurance, or to give a valid discharge for any benefit accruing, or for money payable under the contract, or to contract for the payment of a policy loan, or to contract for any policy change, provided he is fifteen years of age or older on the date he enters into any such contract or gives any such discharge.