The Problem With Tanner Puberty Stages in Child Abuse Cases

Abuse allegations are serious, especially when it comes to children. Perhaps nothing can be worse than to be falsely accused of child sexual abuse or possession of child pornography.

When it comes to allegations of child pornography, taking on a case of this nature can be quite complicated. Oftentimes, law enforcement, child protective services agency social workers, and prosecutors will try to use the Tanner Puberty stages to determine the age of children involved in these allegations.

The Tanner Puberty Stages are typically used to assess the sexual physical development in girls and boys and range from stage 1 (pre-adolescent) to stage 5 (adult). The problem is that using the Tanner puberty stages as evidence of a child’s age in a legal proceeding can lead to false conclusions (and false substantiated findings).

In order to successfully defend against these accusations, you'll need to understand what the Tanner Puberty Stages are, why they were developed, and how to disprove "experts" that try to use it to falsely accuse someone.

What are the Tanner Puberty Stages?

The Tanner Puberty Stages (caution: link to graphic medical images) are shown below for both boys and girls:


Stage 1:

  • No pubic hair
  • Papillar elevation of the breasts
  • Raised nipple

In girls, the first step of puberty begins when the hypothalamus starts releasing the gonadotropin-releasing hormone (GnRH). This hormone then travels to the pituitary gland and the pituitary gland makes two other hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). This usually occurs after a girl's 8th birthday.

Stage 2:

  • Public hair appears
  • Breast bud forms

Breast buds may be tender or itchy and could begin growing at different rates. The uterus gets bigger and the areola may begin expanding.

Stage 3:

  • Coarsening of pubic hair
  • Breast mounds form

Stage 3 typically begins after age 12 and the first signs of acne may appear on the face and back. Hair starts growing under the armpits and the hips and thighs start to build up fat.

Stage 4:

  • Coarse hair spreads across the pubis but still spares the thighs
  • Breasts enlarge to form a mound on mound with a raised areola (the ring of pigmented skin around the nipple)

At Stage 4, puberty is in full swing, and girls usually start this stage at about age 13. Some girls get their first period at this stage and height growth slows down to about two to three inches per year.

Stage 5:

  • Corse hair spreads across the pubis and medial thigh
  • Adult breast contour develops and the areola flattens

Stage 5 usually begins around age 15. The breasts usually reach their approximate adult size and shape, although they can still continue to change up to age 18. Periods become regular and reproductive organs and genitals become fully developed.


Stage 1:

  • No pubic hair
  • No penile or testicular enlargement

Stage 1 might come after a boy's 9th or 10th birthday, but there won't be any noticeable body changes at this stage.

Stage 2:

  • Pubic hair comes in
  • Testicles become enlarged

Stage 2 usually begins around age 11 and the testicles and skin around them (scrotum) get bigger.

Stage 3:

  • Coarsening of pubic hair
  • Penis size and length increases

Stage 3 usually starts around age 13 for boys and they may start having wet dreams. This is when the muscles get larger and the voice begins to "crack."

Stage 4:

  • Coarse hair spreads across the pubis but not the thighs
  • Penis glans and width grows in size

Stage 4 usually starts at age 14 and boys might start to get acne and armpit hair. The deep voice becomes permanent.

Stage 5:

  • Coarse hair spreads across the pubis and medial thigh
  • Penis and testis grow to adult size

Stage 5 typically begins around age 15 and by 18, growth in height slows down. Facial hair starts coming in and boys usually have to begin learning how to shave.

Origin of the Tanner Puberty Stages

The Tanner Puberty Stages were named after James Mourilyan Tanner, a renowned English pediatrician. Dr. Tanner developed the Tanner Stages to grade the level of sexual maturation for breasts in girls, pubic and axillary hair in boys and girls, and genitalia in males.

He did this as part of his work in supervising a long-term study of malnutrition in a large group of British children that lived in an orphanage in Harpenden, England. His work led to the development of modern-day growth charts, as well as a method for characterizing a child's level of sexual maturation.

How to Use Them to Defend Someone Being Falsely Accused of Child Abuse or Possession of Child Pornography

As per Arlan L. Rosenbloom, MD of the Department of Pediatrics at the University of Florida College of Medicine, in cases where the defendant has been accused of possession of child pornography, the Tanner stages have been used to estimate probable chronological age, which isn't sufficient because there are no equations that exist to estimate age from stages. Tanner himself has said the Tanner puberty stages should not be used as evidence of the age of a child. The Tanner puberty stages are not applicable in forensics in this way.

Even if there were equations someone could use to determine a child's exact age, the degree of unreliability in the staging (or the independent variable) would introduce large errors into the estimation of age (the dependent variable).

The Tanner stages were designed to determine development or physiologic age for educational, medical, and sports purposes -- essentially for identifying early and late maturers, not to determine chronological age.

Therefore, if you have been falsely accused of child abuse or possession of child pornography, you can use this information to prove the unreliability of the stage rating. Any "experts" providing testimony as to chronological age based on Tanner staging can be immediately attacked.

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