Mental health is deteriorating(恶化)among young people globally.The incidence of depression and anxiety is increasing, and this not only lowers quality of life, but can have a lasting negative impact as an adolescent reaches adulthood.

Many experts are trying to get at the root causes of this decline, in order to find ways to prevent further deterioration and to provide more effective help when needed. Two “emerging determinants of interest” are (a) over use of screen-based technology, and (b) too little time spent in nature. Most research to date has considered these factors independently, but a group of scientists from University of Adelaide recently decided to look at them jointly, to see if the combination of high screen time (ST) and low “green time” (GT), could affect mental wellbeing.

The result is published on September 4, 2020, in the scientific journal PLOS One. In it, the researchers analyzed data from 186 studies that looked at children's interactions with screen-based technology and nature and their psychological outcomes, including mental health, cognitive(认知的) functioning, and academic achievement.

What they found was that, in general, excessive screen time results in poorer psychological health, whereas green time improves mental wellbeing. Ten years ago in the U.S., the average daily screen time for 8-to-18-year-olds was 7.5 hours. As the study states, “This greatly exceeds recreational ST guidelines of 2 hours or less per day,” and is made even more challenging by the fact that so many schools are using technology to teach classes.

While some screen time can be beneficial, such as promoting connections and enabling tasks to be done more efficiently, there are many ways in which it is harmful. Excessive screen time “replaces important protective behaviors for mental health such as physical activity, getting adequate sleep, in-person social interactions, and academic activities.”

And yet, when children do go outside, they become more physically active. Their day-night rhythm is regulated, thanks to the exposure to sunlight, thus “encouraging healthy sleep-wake cycles and improved sleep, which is key for psychological well-being.”

Often when I mention I have a Ph.D. in physics and astronomy, the response I get from people is “Oh, you must be so smart!” In general, people tend to associate science with “braininess”. It is usually the way society sees scientists versus non-scientists.

Science writer Kat Arney explored this issue in a column for the Royal Society of Chemistry. As she points out, this seemingly unbreakable association between braininess and science influences children’s views of their future. Those who do not see themselves as being among the cleverest in class will automatically discount the idea of a career in a scientific area, even if they find science interesting and do well in the subject.

This stereotype (刻板印象) affects young girls. School-aged girls slightly outperform boys in math and science. However, men take up a bigger amount of positions at science, from undergraduate science majors to administrative positions with the power to hire and promote. In other words, the message of braininess matching scientific skills is applied more heavily to men than to women.

The problem is far worse when the message is used to generalize about groups, especially race. When combined with the cultural belief that only the “brainy” are worthy of scientific training, it becomes a self-reinforcing (自我强化的) cycle. You will hear that African-American under-representation in science is because they are not “smart” enough. In fact, black-majority schools are often underfunded. They lack teachers, supplies and other necessities for STEM preparation. To make matters worse, their students are faced with daily challenges to their intelligence for those who do earn STEM degrees.

The truth is, none of us are born scientists. We often say, “children are natural scientists.” What we really mean is that they are naturally curious and willing to experiment in ways adults are generally trained out of. They have to be taught to channel that curiosity into productive pathways. And we have to do a lot better at not reinforcing the message that scientists are smarter than non-scientist and that only the geniuses can do science.

It’s becoming increasingly vital for individuals to cultivate strong critical thinking skills. Critical thinking involves analyzing information and evidence in a clear, logical, and unbiased way. It’s the ability to ask relevant questions, evaluate information, and come to well-reasoned conclusions.

One of the key benefits of critical thinking is that it can help us make better decisions. By analyzing information carefully, we can avoid making hasty or impulsive decisions that we may later regret. Instead, we can make well-informed choices that are backed by evidence and logical reasoning.

Critical thinking is also essential for academic success. College and university courses require students to read and analyze texts, synthesize information from different sources, and present evidence-based arguments. Without the ability to think critically, students may struggle to excel in their coursework and may be unable to engage in meaningful debates and discussions.

Moreover, strong critical thinking skills are necessary for success in the workplace. Many employers look for individuals who can provide well-reasoned solutions to complex problems, think creatively, and make sound judgments. Critical thinking skills enable us to consider various options and outcomes and weigh the pros and cons of each before arriving at a decision.

Finally, critical thinking is crucial for participation in civic life and democracy. Informed citizens need to be able to evaluate information from different sources and decide which sources are reliable. They need to be able to question assumptions, separate fact from opinion, and make well-reasoned decisions when voting or participating in public debate.

Critical-thinking skills are essential for success in many areas of life. They enable us to make better decisions, excel academically and professionally, and participate effectively in civic life. Therefore, it’s important for individuals to cultivate and develop these skills throughout their lives.