What the research says...
There is no shortage of peer-reviewed studies and professional opinions claiming a direct relational link between the Old Parenting Paradigm [OPP - authoritarian parenting methods, time-outs, punishment, verbal attacks, isolation, conditional love etc.] and childhood issues of low self-esteem, the inability to self-regulate or control, difficulties with school, aggressive behaviors and generally tougher times at home.
The OPP's control-based parenting techniques seek to modify behaviors to the detriment of the child. This style of parenting often unconsciously employs emotional manipulation, excessive praise or in the reverse, yelling, harsh criticism and verbal abuse and places unrealistic demands on a child as a way to gain control.
Dr. Harriet MacMillan and five researchers in Canada found that the children who were spanked or slapped had increased rates of anxiety disorders, anti-social behavior, and depression.
Eric P. Slade and PhD and Dr. Lawrence Wissow conducted a large scale national study of mothers and children. They concluded that "spanking frequency before age 2 is significantly and positively associated with child behavior problems at school age." and that the "introduction of physical punishment before age 2 could be riskier than at older ages..."
"If spanking is applied too frequently or too severely... then it could inhibit a child's development of trust and feelings of security with parents."
" ...children who do not develop a secure attachment to their parents before age 2 are at greater risk for adjustment problems at preschool ages and later, including persistent behavior problems and poorer competence with peers."
Murray Straus, co-director of the Family Research Laboratory at the University of New Hampshire says, "My research has convinced me that there should be no hitting — never, under any circumstances."
In a 1997 study in the Archives of Pediatric and Adolescent Medicine, for example, Straus and two colleagues found that 6- to 9-year-olds whose mothers spanked them at least weekly were
more likely, two years later, to behave antisocially than were kids whose moms didn't spank.