 Of the population in the municipality, 83 or about 42.1% were born in Reisiswil and lived there in 2000.There were 59 or 29.9% who were born in the same canton, while 41 or 20.8% were born somewhere else in Switzerland, and 12 or 6.1% were born outside of Switzerland., children and teenagers (0–19 years old) make up 23.6% of the population, while adults (20–64 years old) make up 61% and seniors (over 64 years old) make up 15.4%.