aikuisia

Aikuisia is Finnish for "adults." It is the plural form of the noun aikuinen and is most often used in the partitive or accusative plural; the nominative plural form is aikuiset. The term refers to people who belong to the adult segment of the population, as opposed to children (lapset) or youths (nuoret). In everyday language aikuisia can appear in statements about size of a group, services, or research samples, for example: "Aikuisia oli paikalla," meaning there were adults present, "Palvelumme on suunnattu aikuisia varten," meaning our service is aimed at adults, and "Tutkimuksessa aikuisia pyydettiin arvioimaan palveluita," meaning adults were asked to evaluate the services.

In Finland, adulthood is defined in legal terms as täysi-ikäisyys, 18 years of age, after which a person gains full civil rights and responsibilities. This has implications for education, work, healthcare decisions, and voter eligibility, and it influences social policies that distinguish between adult and non-adult populations. In sociology and market research, aikuisia is used to describe workforce groups, consumer segments, and demographic analyses.

Etymology stems from aikuinen, the root of meaning mature or fully developed; the form aikuisia reflects Finnish morphology for plural partitive/accusative.