I always thought that parents would appreciate those of us who've chosen not to have children. That choice means more spots in competitive kindergarten class (and college class) for their kids, not to mention a shorter wait for the swings in the park.

But that's not the vibe I've gotten over the years. For some reason, plenty of parents (but certainly not all of them) have turned negative when I talk about being childless — usually after they've asked me when I'm having kids. On the less obnoxious side, I've been told I would "change my mind." I'm now 40 and a got this comment as recently as last week. On the more offensive side, I've been called "selfish" a few times, but I find that response surprising since they don't know my whole story. I have a family rife with mental health issues, addiction problems on both sides, and little money, so I think I'd be taking a huge gamble by reproducing. I'm not sure how that thinking is selfish.

But perhaps the most insulting comment is this: two different parents have insisted that I would never know the "true meaning of life" without kids of my own. Never mind that I cared for my grandmother through the end of her life — a profound and beautiful experience that I value highly. For some people, there's only one experience that counts when it comes to a meaningful life: parenting. (But turn the tables. How crazy would it be if I went around insisting to parents that they don't know anything about being human if they haven't helped someone die?)

As you can probably tell, I've put a lot of thought into not having kids, taking into consideration both practical and personal reasons. I had to, since the default assumption about everyone of a certain age is that they will have a couple of children. Most of the childless people I know have also puzzled through their own particular calculus, and all we want is to be respected for our choices about our own lives. But besides the overt scorn, there's often an I-can't-put-my-finger-on-it sense of derision, even when the decision isn't openly insulted. I long thought this was just paranoia on my part, but a new study shows that my gut feeling is at least partially true.

What the study says

Leslie Ashburn-Nardo, an associate professor of psychology at Indiana University-Purdue University Indianapolis, recently published a study in the journal Sex Roles in which she looked at almost 200 college students' perceptions of those who were childless. Each participant was randomly given a profile of a married man or woman who had chosen to have no kids or two kids. They were then asked to complete a measurement of what they thought the couple's "psychological fulfillment" was — basically to guess about their inner lives.

Ashburn-Nardo found that the childless couples in the study were perceived to be less psychologically fulfilled than those with kids. In a second set of questions, she and her research team also measured how much subjects felt disapproval, anger, outrage, annoyance or disgust toward the fictional people, and found it was "significantly greater" towards the childless subjects, both men and women.

"Our data suggests that not having children is seen not only as atypical, or surprising, but also as morally wrong," writes Ashburn-Nardo in her paper. This is probably because having children has long been — and remains — a norm. That is, it's still assumed of couples that if you can, you do have kids.

Parenthood, writes Ashburn-Nardo, is "both a prescriptive and descriptive stereotype for men and women. [W]hen people violate strongly held norms and expectations such as those regarding parenthood and interest in children ... there are potentially serious consequences. ... This backlash is justified in the minds of perceivers because the targets are thought to have brought it upon themselves by not fulfilling their expected roles."

While it's always reassuring to have one's gut feelings confirmed, this is disheartening news. There are indeed plenty of people out there who find my personal decision not to procreate morally problematic, and they think less of me for it.

Why is this the default answer?

It's incredibly frustrating that a person who has thoughtfully considered parenthood and decided that they aren't going to be able to parent well for a variety of reasons is looked down upon, while plenty of people become parents with far less consideration.

The only way I see to change these assumptions about childless folks is to keep talking about this issue so we can change the norm that being an adult means having kids. Once that norm changes, each person will be able to make the best decision about parenthood for him- or herself — a world where it's not a default to become a parent, but an affirmative choice made with heart and mind. Imagine that — a future society where every kid is planned for and wanted by their parents, and no kid is neglected, ignored, or abused, because they are wanted and loved. If you ask me, that's a worthy goal that would profoundly benefit children.

It's projected that up to a quarter of us won't have kids by 2030 and beyond (currently, almost 20 percent of American adults don't have kids). Naturally, there are many, many ways for childless people to contribute to the future of humanity — and kids' lives. In fact, a high number of educators are childless, preferring to lavish their love and concern for the next generation on young people who aren't genetically related to them. And contrary to popular assumption, plenty of childfree people love kids. (I'd include myself in this category.)

As a friend of mine on Facebook pointed out, some of the negative perceptions of childfree people do seem to be changing: millennials are predicted to include the highest percentage of non-parents of any previous generation, it certainly seems that it's becoming a much less questioned choice among younger people.

But the jury is still out. This new study's subjects were college students, and Ashburn-Nardo told Broadly: "My findings did not differ from those of similar studies conducted in the '70s, '80s, '90s — what I added was the moral outrage explanation. So, despite all the changes in so many other domains in those 40-plus years of studies, the bias against childfree people remains."

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.