Child custody laws use the best interest of the child doctrine to decide the custodial rights of children from broken families. Unfortunately, the best interest of the child doctrine is subjective and ambiguous, thus allowing it to be influenced by a) ideological movements such as feminism and b) third party organisations such as lawyers and psychotherapists. 
child’s wishes (and factors which are relevant to the weight to be accorded these wishes, for example maturity and level of understanding);
child’s relationship with each parent or other people;
effect of change on the child, including separation from parents or other people;
practical difficulty of the child having contact with a parent;
child’s personal characteristics (maturity, sex, background, culture etc.);
need to protect the child from harm; and
possible existence of family violence and family violence orders (s.68F).
Using the argument that the child's wishes do not always entail the child's best interests, the Court has the power to overlook the child's wishes when adjudicating on the child's custodial arrangement.  Speaking hypothetically, this means if a child and a psychotherapist disagree on what is in the child's best interest, a judge can use the argument that the psychotherapist's opinion holds more weight and credibility than the child's wish.
Miss Anne Drist, a feminist-indoctrinated psychotherapist, argues that Jimmy's mother, Jenna Talia-Wartz, is better equipped than his father, Romeo Talia, to care for him. Miss Anne Drist bases her argument on the assertion that mothers are better parents than fathers. She cites a inconclusive study from a feminist lobbyist group to strengthen her argument. Jimmy does not want to live with his mother because she a) brings random men back to her house for sex and b) the unpleasant odour of cigarette tobacco exudes from her clothing. The adjudicating officers are allowed to ignore the child's reasoning and rule in favour of the psychotherapist's speculative theory.
According to feminist ideology, custodial disputes should be decided in favour of mothers. Some judges are known to hold this view. 
The personal opinion of psychotherapists can hold a lot of influence during the adjudication process, and can determine which party obtains custody. Psychotherapists are not required to possess any experience with children. As a consequence, the opinions of many psychotherapists can be impractical. The competence of parents who contest custody of their children is often ignored by psychotherapists who preside over such disputes. 
False accusations of violence and/or sexual abuse are commonly made during custodial hearings. The majority of false accusations made during custodial hearings are left uninvestigated, however they have been used to decide the outcome of such cases in favour of the accusing party.  As a result, some divorce lawyers encourage their clients to falsely accuse their ex-partners of domestic violence and/or child abuse during custodial disputes. 
According to Phyllis Schlafly, a mother is likely to use a 'Three-Step-Technique' to manipulate the system.
Make a false accusation of domestic violence or child abuse against the father
Demand full custody of the children
Demand the collection of child support, alimony, and legal fees.
The technique allows the mother to a) avoid having to prove she deserves to have custody and b) tarnish the reputation of her ex-partner by inciting hysteria against him. Evaluators are known to label a case like this as a high-conflict divorce, using the premiss that shared parenting will not work due to the inability for the parents to resolve their problems in court, full custody is awarded to the mother. The father will be reprimanded by the court if he does not acquiesce, as the court will state he is "not buying into the process". If he tries to defend himself against the accusations that the mother's accusations, he is denied the basic rights a criminal defendant is given such as; "innocent until proven guilty".
The mother does not need to substantiate her accusations. Assuming that the mother's accusations are true, the court does not investigate the validity of her statements. The father is forced to consent to be interrogated and evaluated by court-chosen child-custody evaluators -- the father must pay for these services.
Fathers are sentenced to attend re-education classes and psychotherapy sessions, where they are forced to claim they were at fault. The psychotherapists report back to the court and the father is forced to attend these sessions until he conforms.
Court-approved psychotherapists and lawyers benefit from this process as they recommend the services of each other to their clients. In fact psychotherapists will decline to challenge each other's recommendations or investigate how competent they are, and the lawyers refuse to cross-examine them as they all benefit from continuing business by collecting fees from fathers. 
A noncustodial parent is usually granted the right to visit his/her child. The court will usually state when the noncustodial parent is allowed to visit his/her child. Compliance between the noncustodial and custodial party is expected when the former wishes to visit his/her child. A custodial parent's failure to comply can lead to the court adjusting custody arrangements. However, some courts do not recourse noncustodial parents who are alienated from their children. 
A plethora of studies have found children fare better when they are raised by their biological parents in a normal family setup.
Substance abuse, suicide and overall mortality
The results from Weitoft, Hjern, Haglund & Rosén's study (25 Jan 2003) found children raised in single-parent households are prone to displaying "increased risks of psychiatric disease, suicide or suicide attempt, injury, and addiction."
The researchers adjusted the methodology to rule out the possibility of socioeconomic status, substance abuse and mental illness on the parents' behalf from altering the results. The data from the fine-tuned methodology was the same as the original experiment, indicating that children raised in the single-parent households were far more likely attempt suicide, suffer from a mental illness and develop a disease caused by alcohol and narcotics. Boys from single-parent households were "more likely to develop psychiatric disease and narcotics-related disease than were girls" and were at a heightened risk of "all-cause mortality".
A Finnish study found boys who were raised in single-parent households were more likely to die and commit suicide than boys from two-parent families.
The Office for National Statistics (ONS) of England and Wales found children under four are more likely to die if they are born to single mothers.
A study led by Dr Craig Morgan found children separated from one of their parents for a year or longer are at a prolonged risk of developing schizophrenia.
"We found separation or loss of one or both parents before 16 was associated with a two to three increase in the risk of psychosis", said Dr Morgan".
Dr Morgan's study compared 390 patients with 390 controlled subjects. It was the largest case-control study ever performed on the issue.
A Swedish study found boys raised in single-parent households were "more likely to develop psychiatric disease... than were girls".
Boys raised in single-parent families are at a heighted risk of incarceration. A study on fatherlessness and incarceration (Harper & McLanahan, 2004) found that although "a sizable portion of the risk that appeared to be due to father absence could actually be attributed to other factors, such as teen motherhood, low parent education, racial inequalities, and poverty, adolescents in father-absent households still faced elevated incarceration risks". Surprisingly, it found that the children at most risk were "those in stepparent families, including father–stepmother families".
The U.S. Census Bureau's latest publication (2009) contains data on the custodial arrangement separated parents who held custody of their children in 2008.
A total of 13,743,000 separated parents held custodial rights to their children, 11,356,000 and 2,387,000 of them being mothers and fathers, respectively. Custodial mothers were more likely to be awarded child support: 6,463,000 mothers (56.9%) versus 965,000 fathers (40%).
The average amount set for mothers and fathers was $5,366 and $5,239, though the average received was $3,355 (62.5%) and $3,343 (63.8%), meaning noncustodial fathers handed over a greater sum of money than noncustodial mothers.
Although noncustodial mothers were usually required to play lower amounts in support, custodial fathers were less likely than custodial mothers to receive the full amount owed to them: 371,000 (45.0%) and 2,615,000 (47.1%).
Just over a quarter of the custodial fathers awarded maintenance, 213,000 (25.3%), failed to receive their payments compared to the 1,298,000 (23.4%) for custodial mothers.
Borris, B. Edward. (Jan 1997) INTERFERENCE WITH PARENTAL RIGHTS OF NONCUSTODIAL PARENT AS GROUNDS FOR MODIFICATION OF CHILD CUSTODY Fathers are Capable Too. [Fact.On.CA webpage for article]
Gunilla Ringbäck Weitoft BA, Anders Hjern MD, Bengt Haglund DMS, Måns Rosén PhD. (25 Jan 2003). Mortality, severe morbidity, and injury in children living with single parents in Sweden: a population-based study The Lancet. [The Lancet's abstract of study]
Anu Sauvola, Pirkko K. Råsänen, Mattti I. Joukamaa, Jari Jokelainen, Marjo-Riitta Järvelin, Matti K. Isohanni. (8 Feb 2000) Mortality of young adults in relation to single-parent family background. European Journal of Public Health VOL.II 2001 NO.3. [Eurpub.OxfordJournals.org's study in PDF]