Filipinos highly value reciprocity in social interactions. There are three types of reciprocity: contractual reciprocity involves explicit agreements of equal exchange over a set period of time, like farmers plowing each other's fields. Quasi-contractual reciprocity governs implicit exchanges where repayment terms are unstated. Utang na loob reciprocity refers to repaying favors with interest to avoid "hiya" or shame, and is important in relationships between families.