Table 1 Participant characteristics

Age, years: mean (SD)

21.93 (3.84)

21.27 (3.82)

20.75 (3.29)

Education, N (%)

 Did not complete high school

22 (4.46)

39 (8.84)

16 (4.46)

 Completed high school or equivalent

110 (22.31)

135 (30.61)

91 (25.35)

 Associate college and bachelor degree

315 (63.89)

243 (55.10)

235 (65.46)

 Master’s degree and above

46 (9.33)

24 (5.44)

17 (4.74)

Residence, N (%)

 City

422 (85.60)

364 (82.54)

298 (83.01)

 Town and county

53 (10.75)

67 (15.19)

53 (14.76)

 Country and others

18 (3.65)

10 (2.27)

8 (2.23)

Employment status, N (%)

 Full-time jobs

140 (28.40)

107 (24.26)

66 (18.38)

 Part-time jobs

27 (5.48)

27 (6.12)

31 (8.64)

 Self-employment

50 (10.14)

51 (11.56)

30 (8.36)

 Current not working

26 (5.27)

48 (10.88)

20 (5.57)

 Other jobs

37 (7.51)

32 (7.26)

26 (7.24)

 Never have a job

213 (43.20)

176 (39.91)

186 (51.81)

Current annual income, N (%)

 <¥10,000

282 (57.20)

257 (58.28)

244 (67.97)

 ¥10,000–24,999

42 (8.52)

53 (12.02)

33 (9.19)

 ¥25,000–49,999

64 (12.98)

58 (13.15)

35 (9.75)

 ¥50,000–99,999

64 (12.98)

45 (10.20)

26 (7.24)

 ≥¥100,000

41 (8.32)

28 (6.35)

21 (5.85)

Current marital or intimate relationship status, N (%)

 Single

161 (32.66)

115 (26.08)

113 (31.48)

 Unmarried, but with partner (s)

163 (33.06)

106 (24.04)

79 (22.01)

 Married

3 (0.61)

6 (1.36)

3 (0.84)

 Never have an intimate relationship

166 (33.67)

214 (48.53)

164 (45.68)

Parental education, N (%)

 Below primary school

0 (0.00)

4 (0.91)

1 (0.28)

 Primary school

24 (4.87)

33 (7.48)

14 (3.90)

 Junior high school

84 (17.04)

73 (16.55)

50 (13.93)

 Secondary technical school

61 (12.37)

49 (11.11)

32 (8.91)

 Senior high school

105 (21.30)

70 (15.87)

61 (16.99)

 Associate college

76 (15.42)

77 (17.46)

68 (18.94)

 Bachelor degree

111 (22.52)

94 (21.32)

104 (28.97)

 Master’s degree and above

32 (6.49)

41 (9.30)

29 (8.08)