This book focuses on the effect of psychological, social and demographic variables on student achievement and summarizes the current research findings in the field. It addresses the need for inclusive and interpretive studies in the field in order to interpret student achievement literature and suggests new pathways for further studies. Appropriately, a meta-analysis approach is used by the contributors to show the big picture to the researchers by analyzing and combining the findings from different independent studies. In particular, the authors compile various studies examining the relationship between student achievement and 21 psychological, social and demographic variables separately. The philosophy behind this book is to direct future research and practices rather than addressing the limits of current studies.