These two terms are reciprocal like the grandparent/grandchild terms. Half cousins are descended from half siblings and would share one grandparent. He was an involved parent and grandparent. Lobsang inherited powers directly from his parent; she, indirectly from a foster grandparent (Death). He is an advisory board member for Nevada's Foster Grandparent program. He was Charles Darwin's half-cousin, sharing the common grandparent Erasmus Darwin. Tests can also determine the likelihood of someone being a biological grandparent. He is of Irish descent through a grandparent. There are a few reasons why grandparent involvement is becoming more prevalent. Crossley qualified to play for Wales through a Welsh grandparent. It's very common to use the name of a grandparent as middle name. Grandparent involvement is also common in Eastern societies. "Path halving" makes every other node on the path point to its grandparent. "Path splitting" makes every node on the path point to its grandparent.