Table 4. Multiple Linear regression analysis for predictor variables of happiness in Iranian workers (Iran, 2015) .
| Variable | Level | Score of Happiness | B | p |
| Age | - | - | -0.12 | 0.001 |
| Sex | Male | 141.06 (22.73) | Ref | Ref |
| Female | 144.09 (21.88) | 1.29 | 0.031 | |
| Education | Primary school or lower | 134.93 (25.80) | Ref | Ref |
| Middle school/ high school | 139.48 (23.03) | 3.59 | 0.0001 | |
| College or university degree | 144.19 (21.86) | 7.05 | 0.0001 | |
| Marital status | Single | 141.97 (23.68) | Ref | Ref |
| Married | 141.25 (22.58) | 1.53 | 0.008 | |
| Divorced or widow | 130.32 (26.23) | -9.77 | 0.0001 | |
| Worker’s class | Unskilled worker * | 138.22 (23.54) | Ref | Ref |
| skilled worker | 142.50 (22.28) | 2.64 | 0.002 | |
| Other** | 143.26 (22.82) | 2.95 | 0.0001 |