Variables Students from urban areas ( ) Students from rural areas ( ) valueMean age <0.0001 Major 0.128 Social science 914 (44.1%, 914/2071) 243 (40.6%, 243/598) Natural science 1157 (55.9%, 1157/2071) 355 (59.4%, 355/598) Family style 0.010 Two-parent family 1800 (86.9%, 1800/2071) 495 (82.8%, 495/598) Single-parent or orphaned family 271 (13.1%, 271/2071) 103 (17.2%, 103/598) Average expenditure per month <0.0001 <1000 RMB per month 1216 (58.7%, 1216/2071) 476 (79.6%, 476/598) 1000–4000 RMB per month 820 (39.6%, 820/2071) 111 (18.6%, 111/598) >4000 RMB per month 35 (1.7%, 35/2071) 11 (1.8%, 11/598) Current status of the accommodation <0.0001 In school dormitory 1930 (93.2%, 1930/2071) 531 (88.8%, 531/598) Off-campus apartment 141 (6.8%, 141/2071) 67 (11.2%, 67/598) Personal love status <0.0001 Single 844 (40.8%, 844/2071) 304 (50.8%, 304/598) Being in love or once been in love 1227 (59.2%, 1227/2071) 294 (49.0%, 293/598) Has already experienced sex? 0.859 Yes 426 (20.6%, 426/2071) 125 (20.9%, 125/598) No 1645 (79.4%, 1645/2071) 473 (79.1%, 473/598) Grade 0.654 Freshmen 512 (24.7%, 512/2071) 136 (22.7%, 136/598) Sophomore 638 (30.8%, 638/2071) 202 (33.8%, 202/598) Junior 511 (24.7%, 511/2071) 135 (22.6%, 135/598) Senior 232 (11.2%, 232/2071) 67 (11.2%, 67/598) Graduate students 178 (8.6%, 178/2071) 58 (9.7%, 58/598)