Approximate age of study participants at succeeding waves of data collection
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35

Who was interviewed?

Wave 1     1975

Mother only

Wave 2     1983

Mother & participant

Wave 3      1985-6

Mother & participant; some siblings

Wave 4     1990-3

Mother & participant; some offspring

Wave 5     1995-8

Participant only

Transitions Study    1997-9

240 out of 800 participants

Wave 6    2001-present

Participant only