{
  "research_cutoff": "2026-09-28",
  "type": "Definition audit; no temporal change estimated",
  "rows": [
    {
      "source": {
        "id": "F4",
        "url": "https://www.pewresearch.org/short-reads/2023/10/12/what-does-friendship-look-like-in-america/"
      },
      "publication_year": 2023,
      "measure": "Non-family close friends; count_zero_through_ten_plus",
      "values_percent": {
        "one_to_four": 53,
        "five_or_more": 38,
        "none": 8
      },
      "sum_note": "Rounded categories; not forced to 100",
      "family_excluded": true,
      "response_format": "count_zero_through_ten_plus",
      "fieldwork": "2023-07-17/2023-07-23",
      "sample_size": 5057,
      "sources": [
        {
          "id": "F4",
          "url": "https://www.pewresearch.org/short-reads/2023/10/12/what-does-friendship-look-like-in-america/"
        },
        {
          "id": "F8",
          "url": "https://www.pewresearch.org/wp-content/uploads/2023/10/SR_23.10.12_friendship_topline.pdf"
        }
      ]
    },
    {
      "source": {
        "id": "F5",
        "url": "https://www.pewresearch.org/2025/01/16/where-men-and-women-turn-for-emotional-support-and-social-connection/"
      },
      "publication_year": 2025,
      "measure": "Non-family close friends; any_yes_one_yes_more_than_one_no",
      "values_percent": {
        "at_least_one": 81,
        "none": 18
      },
      "trend_comparable_to_previous": false,
      "family_excluded": true,
      "response_format": "any_yes_one_yes_more_than_one_no",
      "fieldwork": "2024-09-03/2024-09-15",
      "sample_size": 6204,
      "sources": [
        {
          "id": "F5",
          "url": "https://www.pewresearch.org/2025/01/16/where-men-and-women-turn-for-emotional-support-and-social-connection/"
        },
        {
          "id": "F9",
          "url": "https://www.pewresearch.org/wp-content/uploads/sites/20/2025/01/ST_2025.1.16_social-connections_topline.pdf"
        }
      ]
    },
    {
      "source": {
        "id": "F6",
        "url": "https://www.iffs.se/en/publications/journal-articles/dunbar-s-number-deconstructed/"
      },
      "publication_year": 2021,
      "measure": "Comparative group-size inference",
      "finding": "Wide uncertainty undermines a precise universal 150-person threshold"
    },
    {
      "source": {
        "id": "F7",
        "url": "https://www.psy.ox.ac.uk/publication/634861"
      },
      "publication_year": 2016,
      "measure": "Mobile-call network structure",
      "finding": "Layering evidence; not self-reported close-friend census"
    }
  ],
  "comparison_note": "Both source questionnaires exclude family. Question wording/response categories and samples differ. No causal attribution to wording or family inclusion, and no clean longitudinal trend inferred."
}