A startling Time magazine cover image of a mother breastfeeding her three-year-old son has sparked debate about the technique known as attachment parenting.
Jamie Lynne Grumet, 26, appears on the latest US edition's cover with her son Aram, 3, as he stands on a small seat to reach her.
Grumet explains in the story that she uses the same attachment method on her adopted five-year-old son Samuel, who she adopted from Ethiopia in 2010 and continues to breastfeed about once a month. She also says that her mother breastfed her until she was six.
She told the magazine she remembered being latched onto her mother's breast.
"It's really warm. It's like embracing your mother, like a hug. You feel comforted, nurtured and really, really loved. I had so much self-confidence as a child, and I know it's from that."
Grumet said being able to breastfeed Samuel after his adoption helped comfort him following the trauma he had faced.
"I didn't realise how much it would help my attachment to him.
"When his English improved, because the connection was there, he didn't do it as much."
Grumet has written on her blog, which has since crashed due to increased web traffic, about how much Aram, who will turn four next month, enjoys being breastfed.
One post features a picture of Aram being breastfed at the the Playboy mansion with the caption: "I've breastfed Aram at the Playboy mansion. I actually felt it was the most appropriate place on earth to do it," the Dail Mail reported.
Attachment parenting, a phrase coined by US pediatrician Dr William Sears, was first suggested as a theory in the 1950s and has since developed into a method that has created some controversy - because of the age at which people continuing breastfeeding their children and the use of co-sleeping.
Professor David Fergusson, director of Otago University's Christchurch Health and Development Study, said he was unaware of any evidence showing prolonged breast feeding had any great benefits.
Attachment was one of two basic approaches to addressing child behaviour, with the other focused on social learning.
The social learning programmes dealt with teaching parents skills to manage behaviour, such as non-punitive parenting, use of rewards, and timeouts. They had been evaluated properly and been found to be very effective in managing behaviour problems.
Before anyone invested in an attachment approach they needed to be sure the programme had been evaluated using a randomised control trial in which a group of parents using the programme were compared to a group who were not.
That approach had been used on the social learning programmes, but he had not come across any such trials evaluating attachment parenting, Fergusson said.
"Before any investment is made in this area, there is a need for thorough evaluation. There is no evidence I am aware of that prolonged breast feeding has any great benefits."
Breast feeding of babies had been shown to have small benefits in areas such as IQ and allergies. While prolonged breast feeding probably would not do any great harm, it may not do any good, either.
"My advice, as with all things, is that the consumer should check out the validity of the claims."
He doubted many people would consider prolonged breast feeding to be a realistic option .
Practical factors mitigating against it included the development of teeth, which were the "surest sign" that children were ready to leave the breast.
"It seems to be a sensible developmental sign that a child is ready to move away from the breast and into eating. Why would you grow teeth if you don't need to use them?"
What appeared to have happened was that a group of people with strong ideas about the importance of attachment and bonding had developed a theory, based on weak evidence, and aggressively promoted it.
Such things had happened time and again in the area of child development and parenting.
Time managing editor Rick Stengel said he had not heard of any retailers concerned about displaying the cover. But he acknowledged that the image was "provocative".
"We're posing an interesting question about a subject that couldn't be more important - how we raise our children. People have all kinds of mixed feelings about that."
Retail chains including Target, Wal-Mart and Safeway did not immediately respond to requests for comment on whether the magazine, which goes on sale Friday, would be displayed in stores.