The table below shows the sample descriptions of the three age groups. Most characteristics were significantly different across the age groups. However, happiness was not different.

Table I. Description of the samples. Variables Happiness Age Gender: Female Male Education year Marital status: No spouse Having a spouse Living place: Urban area Town Rural area Living arrangement: With others Alone BMI Religion belief: No Yes Chronic diseases: No Yes Self-rated health: Good Poor Smoking: Never Quit Smoking Drinking: Never Social Light Heavy Regular exercise: No Yes Internet using: No Yes Mood Family social support Friends/colleagues/ neighbors social support Formal social support Work: No Yes Social group participation Social trust Subjective economic status Social class Life control Quality of life Young (n = 824) Middle-aged (n = 978) Old (n = 397) Mean (SD) or % 4.03 (0.83) 28.62 (6.22) 48.3% 5 | .7% I450 (2.58) 68.4% 3 I .6% 60.0% 28.6% | |.4% 93.6% 6.4% 22.80 (4.2 I) 34.6% 65.4% 89.4% I0.6% 8 I 0% | 9.0% 35.8% 2.5% 6 I .7% 59.0% 29.6% 8.5% 2.9% 52.6% 47.4% 5.6% 94.4% I I.8l (4.I I) 7.27 (3. I 0) 5.97 (I .83) 2.96 (0.77) 23.3% 76.7% 2. I 8 (I .08) 2.33 (0.79) 3.04 (. I 7) 5.03 (I .45) 6.74 (I .94) 2.83 (0.58) Mean (SD) or % 3.93 (0.93) 5 I .89 (7.08) 52. I % 47.9% I I.24 (3.76) I9.2% 80.8% 53.9% 27.0% | 9. | % 93.8% 6.2% 24.27 (3.39) | 5.9% 84. I % 62.6% 37.4% 79.8% 20.2% 33.9% 4.9% 6 I . I % 66.4% I8.6% 7.5% 7.6% 47.8% 52.2% 53.9% 46. I % Io.93 (4.44) 7.63 (3.93) 4.82 (I .73) 2.92 (0.85) 3 I.0% 69.0% 2.03 (I .07) 2.06 (0.87) 2.87 (I. I4) 4.9I (I64) 6.88 (2. I 2) 2.83 (0.62) Mean (SD) or % 3.95 (0.99) 73.75 (6.59) 5 I .6% 48.4% 8.5I (3.94) 34.0% 66.0% 50.5% 23.6% 25.9% 93.5% 6.5% 23.92 (3.27) | 2.6% 87.4% 35.7% 64.3% 72.3% 27.7% 30.2% 7.6% 62.2% 78.6% | 2.8% 3.5% 5.0% 44. I% 55.9% 92.4% 7.6% I I.50 (4.98) 7.66 (3.95) 4.23 (0.09) 2.90 (0.89) 83.8% I6.2% I.84(I.I6) I.99 (0.80) 2.68 (I . I 3) 4.86 (I .77) 6.89 (2.43) 2.85 (0.59) Signicance >lllllllll