For years, scientists thought children in poverty experienced a huge word gap, hearing 30 million fewer words by age 3.

Now,  research  from MIT is the latest to show the  20-year-old  findings are outdated and could even be damaging.

In the 1990s, researchers spent two and a half years visiting the homes of families with young children, starting when the kids were seven months old.

The families varied in levels of income and education.

The researchers recorded the conversations and later transcribed them to come up with their findings.

Their results popularized the idea of a "word gap" between higher- and lower-income families.

This study has since been cited in at least 8,000 academic publications.

The research also drew attention to early childhood education.

Today, however,  critics say  the original study is antiquated and could be contributing to discrimination in education. "It was a different time," said Rachel Romeo, MIT postdoctoral research fellow and lead author of the study. "There were different scientific standards.

It is a bit outdated." In the latest study, Romeo and her MIT team recorded the conversations 4- to 6-year-olds were having each day.

They also analyzed MRIs of their brain pathways.

They found talking with kids 6 and younger helps their brain development, regardless of their socioeconomic background.  "This relationship between conversational turns and brain structure was independent of socioeconomic status.

So even children from the lowest income groups who experienced lots of conversations had really strong brain connections.

And these brain connections are what predicted their language skills," Romeo said.

And this study pulled from a much deeper sample than the 1990s research did.

Back then, researchers only spent an hour per week in each home and only studied 42 families.

MIT also used measures to prevent observer bias, another critique of the word gap study.

With observer bias, the presence of a researcher can intimidate or compel parents to talk more or less.   SEE MORE: What Does The Word Gap Mean For Kindergarten Students? "There's been a lot more research over the last couple of decades with much more advanced technology that can look at much longer periods of time in children's lives.

We particularly used a particular recorder called  Lena  that records entire days of children's experience," Romeo said.

Moving forward, Romeo suggests changing the way people talk about learning could be better for kids.

And that researchers should consider the word counts kids learn as a difference rather than a gap.

As far as her work, the main takeaway is clear: Any adult having back-and-forth conversations could help a child's brain grow.