Favoring specific groups during recruitment.

Voters rank candidates by preference.

an experimental method in developmental psychology used to gain insight into the young mind/brain.

A preferential creditor (in some jurisdictions called a preferred creditor) is a creditor receiving a preferential right to payment upon the debtor's bankruptcy under applicable insolvency laws.

Bias towards linking with popular nodes.

A preferential trade area (also preferential trade agreement, PTA) is a trading bloc that gives preferential access to certain products from the participating countries.