aikuinen

Aikuinen is Finnish for adult. In general use, it refers to a person who has reached the stage of life in which most legal rights and responsibilities apply, and who is considered socially capable of independent decision-making. The term contrasts with a child (lapsi) or a young person (nuori).

In Finland, the age of majority is 18. At this age a person typically gains full civil capacity, including the right to vote in elections, to enter into contracts, and to be legally responsible for their acts. Some rights or duties may be restricted or conditioned by age in specific contexts, but 18 is the standard threshold for legal adulthood. Adulthood does not automatically equate to complete independence or maturity; many adults continue to study, rely on support networks, or experience ongoing development in areas such as judgment and planning.

Biological and psychological maturation continues into early adulthood for many individuals, with improvements in executive functions, self-regulation, and long-term goal setting often occurring in the mid-to-late twenties. Social expectations commonly place adults in roles such as worker or student, caregiver, or citizen participant in civic life. Cultural norms can influence when people are considered fully grown or ready for certain responsibilities, and different contexts may define adulthood differently in law, family life, or social practice.

Overall, an adult or aikuinen is defined by a combination of legal status, physical and psychological maturity, and social responsibility, with the precise boundaries shaped by context and jurisdiction.