We extend prior research on involvement in employee development activity by including prominent individual difference constructs that have been previously ignored in this area of research. These include two important personality characteristics (conscientiousness and openness to experience), mental ability and goal orientation constructs. We tested both mediated and direct effects of the variables. The sequence of relationships observed in the model was: "general personality traits" [right arrow] "development domain individual and situational variables" [right arrow] "development domain motivational variables" [right arrow] "involvement in development". Personality had indirect (mediated) effects on motivational and involvement constructs while goal orientation, as a development domain individual variable, had direct effects on motivational constructs. Mental ability had no effects. The study also replicated core relationships from prior research, but did so using an Internet sample and response medium. The model presented provides the most complete picture of behavior in this area to date. Important implications for advancement of theory, research and practice in the area of employee development behavior are discussed.