by Jenna Somers
When a first grader has a spelling test on a Friday, they probably understand that the more they study throughout the week, the better they'll perform on the test. They also probably understand that if they only study on Monday, then by Friday, they may not remember how to correctly spell all the words. That said, if shown the correct spelling, they will most likely admit that their spelling was incorrect.
This line of thinking demonstrates children's appreciation for the influence of time on their knowledge and their capacity to understand that their beliefs can be false. These cognitive skills are associated with children's theory of mind, more advanced brain function that gives children the ability to reason about and understand their and others' thought processes and feelings.
Humans seem to develop this higher-order cognition as young children, but specifically when and how children understand time sensitivity to knowledge and false beliefs is the subject of Wen Lu's research as a second-year Ph.D. student in the Psychological Sciences Program at Vanderbilt University Peabody College of education and human development.
Real-world implications
According to Lu, developmental milestones associated with theory of mind are important because they predict outcomes related to social skills and acceptance as well as moral reasoning. Delayed development of these processes, particularly a child's difficulty in understanding that their beliefs can be false, may suggest the child has a developmental abnormality. Theory-of-mind is also critical to teaching and learning, which requires the consideration of others' knowledge status, intentions, desires, and emotions.
"If we can understand on average when children develop this reasoning, we may be able to improve assessments for developmental delays and abnormalities, as well as interventions to teach children with delays better approaches for learning new information," said Lu, a researcher in the Social Cognition lab led by Jonathan Lane, associate professor of psychology and human development.
Furthermore, understanding when children typically develop theory of mind skills could help families and teachers reinforce better study habits among children. "It's also important for children's mental health," Lu said. "Rather than performing poorly on a test and thinking they are not smart, they can reflect on how much time they studied and then change their study behaviors to improve on the next test."
Time sensitivity of knowledge and false belief recognition
Preliminary data from Lu's "Time sensitivity of knowledge" study demonstrates that children experience a significant shift in their reasoning between ages 4 and 6.
In the study, Lu shows two videos to 4-to-6-year-old children. The first video helps assess children's understanding of the idea that knowledge increases with the duration of learning time. One character looks into a box with toys for 10 seconds, and then another character looks into the same box for one second. The children are then asked which character will remember more toys from the box.
The second video helps assess children's understanding of the idea that knowledge decreases with the duration of elapsed time after learning. One character opens a box and looks at the toys inside. She then leaves to do other activities, such as playing a puzzle with her friend who has not yet looked in the box. When they return, the friend looks in the box, and then the children are asked which character forgot what toys were in the box.
In both of these video-based assessments, children were not able to understand the effects of time on knowledge until 5 years old, which aligns with when they know their beliefs can be false.
For this study, Lu also created a video of a false belief task. Children ages 4 to 6 years old see a crayon box and are asked what they think is inside. Of course, they say crayons. In another video clip, someone opens the box to reveal lollipops inside. The children are asked what they thought was inside the crayon box when they first saw it. Most children close to age 5 and older admit they thought crayons were inside the box, but the younger children insist they knew lollipops were inside all along.
"The younger children cannot deal with the fact that their beliefs could be false. That is a pretty big difference in children's reasoning between ages 4 and 5. They can come to understand that what's in their mind may not be a true reflection of reality," Lu said.
Wen Lu's journey to Vanderbilt
In China, Lu was a simultaneous interpreter of English and Chinese from 2014 to 2021. She interpreted and translated for people in the education, automotive, and pharmaceutical industries, among many others. The demands of the job sparked her interest in the cognitive processes of how memory works for learning new information. During this time, she earned a master's degree in interpretating and translating from the University of Bath in the United Kingdom. In 2019 she began a master's degree program in teaching and learning at the University of Pennsylvania but transferred to interdisciplinary studies in human development after taking a human development course and realizing her passion for the subject. In 2023, she joined Vanderbilt's Psychological Sciences doctoral program, where she investigates questions about the mind and memory that harken back to her initial interests as an interpreter and translator.
After she graduates from Vanderbilt, Lu plans to pursue a career in academia, committed to understanding the development of reflective processes and helping children better regulate their thinking, so that they can become sophisticated learners and consumers of information.
