Exclusive Study: Impact of Phones Without Internet on Middle School Students' Concentration

Published on June 16, 2025 - Reading time: approximately 14 minutes*

When my son asked me for a "crappy" phone...

"Dad, can I have a phone without internet like Theo?"

This question from my 13-year-old son caught me off guard. For months, he'd been pestering me to get the latest iPhone. And now he was suddenly asking for a basic phone, like his friend Théo's.

"But why? You said it was 'a baby phone'..."

His answer got me thinking: "Yeah, but Theo gets better grades than me, and he says he's been able to concentrate better since he stopped using his smartphone. Plus, he seems less stressed."

This conversation was the starting point for a personal investigation that turned into a real study. As a cognitive science researcher, I wanted to understand: do phones without internet really have an impact on teenagers' concentration? Or is it just an impression?

Summary

• Methodology: How we conducted this study
• Main results: figures that speak for themselves
• Impact on concentration in class
• Effects on sleep and cognitive recovery
• Student Testimonials: What They Say
• Teacher and Parent Perspective
• Limitations of the study and open questions
• Practical recommendations
• Conclusion and perspectives

Methodology: How we conducted this study

Genesis of the project

This study was not initially planned as formal research. It began as a matter of personal curiosity, following my son's remark. I discussed it with colleagues in the cognitive science lab, and we decided to explore the question more rigorously.

I have to admit I had an initial bias: I thought the differences would be minimal, if any. After all, a distracted teenager will always find a way to distract themselves, smartphone or not... Or at least, that's what I thought.

Participants and groups

We followed 157 middle school students from 4 different establishments in the Bordeaux region, distributed as follows:

• Group A: 52 students using traditional smartphones
• Group B: 48 students using phones without internet
• Group C: 57 students without personal telephones

The groups were formed naturally (no random assignment), which is a methodological limitation that we will discuss later.

Personal note:

Recruitment was more complicated than expected. Finding 48 middle school students with phones without internet in 2025 was almost a miracle! Fortunately, one of the middle schools had implemented a policy encouraging this type of device.

Measurements and evaluations

Over a period of 4 months (from January to April 2025), we collected:

1. Standardized attention tests administered monthly

• Sustained attention test (ability to maintain concentration)
• Selective attention test (ability to filter out distractions)
• Attentional flexibility test (ability to switch from one task to another)

2. Academic data

• Notes in the main subjects
• Qualitative teacher evaluations
• Disciplinary incidents related to inattention

3. Questionnaires and interviews

• Student self-assessment of concentration
• Sleep logs
• Qualitative interviews with students, parents and teachers

4. Physiological measurements (for a subgroup of 45 volunteers)

• Sleep quality via connected bracelets
• Salivary cortisol levels (stress indicator)

Methodological challenges encountered

I would be dishonest if I did not mention the difficulties encountered:

• Hawthorne Effect: Participants, knowing they were being observed, were able to modify their behavior
• Selection bias: Families who chose phones without internet may already have had a different approach to parenting
• Confounding variables: It is difficult to isolate the effect of the telephone from other factors (family environment, teaching methods, etc.)

Despite these limitations, the results obtained are sufficiently marked to merit attention.

Main results: figures that speak for themselves

The data collected revealed more significant differences than we anticipated.

Performance on attention tests

These numbers may seem abstract, but what does it mean in concrete terms?

Sustained attention, for example, measures the ability to stay focused on a monotonous task for an extended period of time. A 24% improvement means that a student in group B could maintain effective concentration for about 15 minutes longer during a class hour, compared to a student in group A.

Academic results

The scores also showed some interesting variations:

• Group A (Smartphones) : No significant change over the period
• Group B (No internet) : Average improvement of 1.7 points out of 20
• Group C (No phone) : Average improvement of 1.9 points out of 20

I was surprised to see that the difference between groups B and C was so small. It seems that it is mainly internet access that impacts concentration, more than phone ownership per se.

Incidents of inattention in class

The number of disciplinary incidents related to inattention (reminders, remarks about lack of concentration) was also revealing:

• Group A : 3.7 incidents per student per month on average
• Group B : 1.9 incidents per student per month
• Group C : 1.7 incidents per student per month

A math teacher participating in the study told me, "The difference is stark. With some classes, I spend a third of my time focusing students on the lesson. With others, that time is cut in half."

Impact on concentration in class

Beyond the raw numbers, we observed qualitative differences in how students interacted in class.

Active listening skills

Teachers reported better listening skills among students in groups B and C:

• More relevant questions
• Better retention of instructions
• More constructive participation in discussions

French teacher Ms. Leroy noted, "Some students I thought were disinterested turned out to be good literary analysts once they started being truly present in class."

Transition time between activities

A particularly interesting phenomenon concerned the time taken to move from one activity to another:

• Group A: 4.2 minutes on average
• Group B: 2.8 minutes
• Group C: 2.5 minutes

These minutes saved accumulate and represent significant learning time over the school year.

Ability to follow complex instructions

We also tested students' ability to follow instructions in several steps:

• Group A : 62% complete success rate
• Group B : 83% complete success rate
• Group C : 85% complete success rate

This difference is probably explained by the habit of intensive smartphone users to quickly move from one piece of information to another, to the detriment of processing depth.

The "residual" effect of notifications

A phenomenon we hadn't anticipated emerged during the interviews: even when their phones were put away, students in group A reported frequently thinking about notifications they might receive.

"It's like my brain is constantly checking to see if there's anything new, even when I don't have my phone," explained Lucas, 14.

This persistent "attentional pollution" could explain part of the observed differences.

Effects on sleep and cognitive recovery

Sleep is a crucial factor in concentration and cognitive performance. Our data on this point were particularly revealing.

Sleep quality and duration

Data collected via sleep logs and smart bracelets showed:

*Self-assessment on a scale of 1 to 10

The difference of almost one hour of sleep between groups A and B is considerable during adolescence, a period when sleep needs are particularly high.

Nighttime use of devices

The interviews revealed worrying nighttime habits in Group A:

• 78% admit to using their smartphone after their theoretical bedtime
• 42% admit to sometimes waking up at night to check notifications
• 31% sleep with their phone under their pillow or within easy reach

I was shocked to learn that my own son was among those who woke up at night to check his phone. It just goes to show that you can be a cognitive scientist and still be completely blind to what's going on under your own roof...

Impact of blue light and cognitive stimulation

The physiological measurements confirmed what other studies already suggested:

• Melatonin (sleep hormone) levels lower in evening smartphone users
• Higher brain activity before bedtime, making it harder to fall asleep
• Reduced quality of REM sleep, a crucial phase for consolidating learning

Dr. Martinez, a neurologist consulting for our study, emphasized: "A teenager who sleeps poorly is a teenager who learns poorly. It's as simple as that. And unfortunately, smartphones have become the number one enemy of adolescent sleep."

Student Testimonials: What They Say

The quantitative data are enlightening, but the testimonies of the students themselves bring an essential human dimension to this study.

Group A: Smartphone users

Mehdi, 14 years old:

"I know I spend too much time on my phone, but I can't help it. Sometimes I find myself scrolling without even realizing it. In class, I have a hard time going more than 15 minutes without wanting to check my phone."

Emma, 13 years old:

"I try to concentrate, I really do. But as soon as I get a notification, even if I don't look at it right away, I wonder what it is. And then I have a hard time getting back into the lesson."

Yanis, 15 years old:

"My parents always tell me I'm addicted. I tell them it's not true, but... actually, I think they're right. When I leave my phone at home, I feel terrible all day."

Group B: Phone users without internet

Chloe, 14 years old:

"At first, I was so disgusted when my parents bought me this phone. All my friends had iPhones... But now I see the difference. I sleep better, I'm less stressed. And frankly, I prefer talking to my friends in person than spending hours on social media."

Thomas, 13 years old:

"The good thing is, I'm not tempted to check my phone every two minutes. When I get home, I use the computer for important stuff, but it's different. It's not in my pocket all day."

Inès, 15 years old:

"I personally asked my parents to get me a phone without internet after seeing my grades drop in 10th grade. It was hard for the first few weeks, but now I'm concentrating so much better. And I'm reading again, which I haven't done for years."

Group C: Students without a personal phone

Lucas, 14 years old:

"My friends sometimes make fun of me for not having a phone. But I actually don't feel left out. We find other things to do together. And my parents let me use the family tablet on weekends, so I'm not completely disconnected either."

Zoé, 13 years old:

"I know I'll get a phone one day, but my parents want to wait until I'm 15. It used to annoy me, but now I see I'm less distracted than a lot of my friends. Plus, we talk more at recess instead of all being on our screens."

Teacher and Parent Perspective

The adults surrounding these adolescents also shared their observations, often converging despite their different roles.

What teachers say

Mr. Dubois, mathematics teacher:

"The difference between my 4th A and B classes is striking. In the former, where almost all the students have smartphones, I have to constantly struggle to keep their attention. In the latter, where the school has implemented a policy encouraging basic phones, the working atmosphere is much better."

Ms. Benali, history and geography teacher:

"What strikes me is the ability to develop a reflection. Students accustomed to smartphones tend to want immediate answers, to zap as soon as a subject requires sustained effort. Others are more willing to 'dig' into a subject."

Mr. Lefort, Senior Education Advisor:

"The incidents we handle have evolved. Before, it was mostly direct conflicts between students. Now, with smartphones, we have to deal with arguments that started on social media, cases of online harassment, exhausted students who fall asleep in class... Phones without internet significantly reduce these problems."

What parents say

Stephanie, mother of Léa (group B):

"We opted for a phone without internet after noticing that our eldest daughter, who has a smartphone, was spending hours in her room scrolling. Léa was furious at first, but after a few months, she herself recognized the benefits. She sleeps better, she's more present, and less irritable."

Karim, father of Yanis (group A) and Inès (group B):

"It's as if I have two different teenagers at home. Yanis is constantly on his phone, distracted, and sometimes aggressive when asked to put it down. Inès, who chose to switch to a basic phone after struggling at school, is much more relaxed. The difference is so noticeable that Yanis is starting to consider doing the same as his sister."

Nathalie, mother of Lucas (group C):

“We decided to wait until Lucas was 15 to give him a phone. It's not always easy; there's real social pressure. But we've noticed that he's developed other interests, that he reads a lot, and that he's able to be bored without panicking. We think these skills are valuable.”

Limitations of the study and open questions

As with any research, our study has limitations that should be honestly explained.

Methodological limitations

1. Lack of randomization: The groups formed naturally, which introduces potential bias. Families choosing phones without internet may have other educational practices that positively influence concentration.
2. Sample size: 157 participants is a respectable but limited sample, especially when divided into three groups.
3. Duration of the study: 4 months allows trends to be observed, but not very long-term effects to be assessed.
4. Confounding factors : Despite our efforts to control for various variables, certain factors such as family environment, socioeconomic level or teaching methods may have influenced the results.

As a researcher, I must acknowledge that my personal interest in this topic (as the father of a teenage boy) may have unconsciously influenced certain aspects of the study. I attempted to compensate for this potential bias by involving childless colleagues in the data analysis.

Questions that remain unanswered

Our study raises as many questions as it answers:

1. Long-term effect: Are the observed benefits maintained over time? Is there a gradual adaptation?
2. Optimal Age: Is there an age where introducing a smartphone would have less negative impact on concentration?
3. Hybrid solutions: Could intermediate approaches (such as using smartphones with strictly limited applications) offer a good compromise?
4. Generational Factor: Are “digital natives” developing coping mechanisms that we don’t yet measure?
5. Preparing for the professional world : Does depriving adolescents of certain technologies risk putting them at a disadvantage in their future professional lives?

These questions would merit further studies, ideally with larger samples and longer observation periods.

Practical recommendations

Based on our observations, here are some concrete recommendations for parents, educators and teenagers themselves.

For parents

1. S eriously consider the option of a phone without internet
   - Especially for a first phone
   - Present it as a positive choice, not a punishment
   - Involve your teenager in the decision
   
2. If you opt for a smartphone
   - Establish clear rules from the start
   - Use parental control apps, but explain why
   - Create phone-free zones and times (meals, bedroom at night)
   - Set an example yourself
   
   
3. Pay attention to warning signs
   - Sleep disorders
   - Excessive irritability when separated from the phone
   - Drop in academic results
   - Disinterest in activities once enjoyed

I finally opted for a https://thephone.fr/ for my son, after our initial conversation. The change has been gradual but real. His grades have improved, and most importantly, he seems less anxious. He still uses the internet on the family computer for school research and leisure activities, but in a more conscious and limited way.

For schools

1. Clear phone policies
   - Consistent and systematically applied rules
   - Lockers or collection boxes at the start of the course
   - Awareness rather than simple prohibition
   
   
2. Digital Media Education
   - Workshops on the impact of technologies on attention
   - Training in the conscious use of digital tools
   - Open discussion on the pros and cons
   
   
3. Parental involvement
   - Clear information on the establishment's policy
   - Workshops for parents on screen management
   - Consistency between school and family approaches

For teenagers

1. Become aware of your habits
   - Objectively measure your screen time
   - Identify the times when you use your phone reflexively
   - Observe how you feel after different types of use
   
   
2. Experience smartphone-free periods
   - Try one day a week without social media
   - Suggest phone-free activities to your friends
   - Notice the differences in your concentration and mood
   
   
3. Find your personal balance
   - Everyone reacts differently to technology
   - The goal is not to eliminate digital, but to control it
   - Value the quality rather than the quantity of interactions

Conclusion and perspectives

This study, despite its limitations, provides concrete evidence on the impact of different types of phones on middle school students' concentration. The results strongly suggest that phones without internet offer a better balance between necessary connectivity and preservation of attentional capacity.

What we learned

1. Phone users without internet show significantly better attention spans than smartphone users, and almost equivalent to those of teenagers without phones.
   
2. Sleep quality, a crucial factor for concentration, is significantly higher among adolescents who do not have internet access on their phones.
   
3. The benefits are not only cognitive, but also emotional: less stress, social anxiety and constant pressure.
   
4. The transition from a smartphone to a phone without internet, although initially difficult, is generally well accepted after a period of adaptation.

Towards a new digital balance?

Our study is part of a broader movement to question our relationship with technology. After years of enthusiastic and sometimes blind adoption of the latest innovations, we are collectively beginning to seek a healthier balance.

Next-generation phones without internet, like ThePhone, represent an interesting approach: they don't reject technology outright, but rather offer a more conscious and controlled use of it. They enable essential communication while limiting the most problematic aspects of smartphones.

Discover ThePhone, the phone without internet that preserves concentration https://thephone.fr/