title: Smartphone usage in the 21st century: who is active on WhatsApp?
abstract: BACKGROUND
  Mounting evidence shows that smartphone usage heavily disrupts our work life and social activities. Moreover, it is possible that overuse could resemble addictive tendencies. A key contributing factor to smartphone overuse seems to be usage of the messaging application WhatsApp. Although WhatsApp is one of the most commonly used communication applications on smartphones, research in this area is scarce. Given the huge societal debate on the impact of smartphone usage on our daily lives, the present study undertook a large-scale investigation in order to provide numbers on smartphone usage generally-and use of WhatsApp in particular, with the aim of providing a basis for a scientific debate.
  
  
  METHODS
  In a large sample of N = 2,418 users, we recorded WhatsApp behaviour over a 4 week period.
  
  
  RESULTS
  Our data show that use of WhatsApp accounted for 19.83% (= 32.11 min) of all smartphone behaviour (compare: Facebook only 9.38% = 15.19 min). The mean of general daily smartphone usage was 161.95 min. Females used WhatsApp for significantly longer periods of time than males and younger age was associated with longer duration of WhatsApp use. While the personality trait Extraversion was positively associated with daily WhatsApp use, Conscientiousness showed an inverse correlation with the length of daily WhatsApp use.
  
  
  CONCLUSIONS
  The numbers on smartphone usage in the present study show that the smartphone dominates our daily life. In particular WhatsApp is a driving force, here. Given the length of daily smartphone and WhatsApp usage, more studies need to be conducted to better understand smartphone usage.
authors.affiliation: Institute of Psychology and Education, Ulm University, Ulm, Germany. christian.montag@uni-ulm.de.|Molecular Psychology, Zentrum für Biomedizinische Forschung, Helmholtzstr. 8/1, 89081, Ulm, Germany. christian.montag@uni-ulm.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Montag
authors.affiliation: Department of Informatics, University of Bonn, Bonn, Germany. konrad.blaszkiewicz@gmail.com.
authors.forename: Konrad
authors.initials: K
authors.lastname: Błaszkiewicz
authors.affiliation: Institute of Psychology and Education, Ulm University, Ulm, Germany. rayna.sariyska@uni-ulm.de.
authors.forename: Rayna
authors.initials: R
authors.lastname: Sariyska
authors.affiliation: Institute of Psychology and Education, Ulm University, Ulm, Germany. bernd.lachmann@uni-ulm.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Lachmann
authors.affiliation: Department of Informatics, University of Bonn, Bonn, Germany. ionutandone@yahoo.com.
authors.forename: Ionut
authors.initials: I
authors.lastname: Andone
authors.affiliation: Department of Informatics, University of Bonn, Bonn, Germany. trendafilov.boris@gmail.com.
authors.forename: Boris
authors.initials: B
authors.lastname: Trendafilov
authors.affiliation: Department of Informatics, University of Bonn, Bonn, Germany. eibes@cs.uni-bonn.de.
authors.forename: Mark
authors.initials: M
authors.lastname: Eibes
authors.affiliation: Department of Informatics, University of Bonn, Bonn, Germany. alex@iai.uni-bonn.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Markowetz
mesh_terms: D000293:Adolescent; D000328:Adult; D003142:Communication; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D063731:Mobile Applications; D000068997:Smartphone; D060756:Social Networking; D060145:Text Messaging / Q000706:statistics & numerical data*; D055815:Young Adult