In May 2025, Tran Thi Thu Thuy and four colleagues published "Bridging Human Behavior and Environmental Norms: A Cross-Disciplinary Approach to Sustainable Tourism in Vietnam" in Sustainability (MDPI), Vol. 17, Issue 10. It's a methodologically rigorous attempt to answer a long-debated question in tourism behavioural research: what actually makes a tourist behave sustainably — rational choice or moral obligation?
The answer, in the Vietnamese context: moral obligation, more than rational choice. And the implications for how the country's tourism operators should design and market sustainable products are substantial.
What the study did
Methodology
- Sample: 549 Vietnamese tourists, recruited via stratified sampling across three major regions of Vietnam (covering North, Central, and South).
- Theoretical frame: integrated two well-established models —
- Theory of Planned Behavior (TPB) — Attitude, Subjective Norms, and Perceived Behavioral Control all shape Behavioral Intention, which then drives behaviour.
- Value-Belief-Norm theory (VBN) — Environmental Awareness shapes Altruistic and Biospheric Values, which activate the New Environmental Paradigm worldview, which forms Personal Norms, which drive behaviour.
- Analysis stack: Exploratory Factor Analysis → Confirmatory Factor Analysis → Structural Equation Modeling (SEM) → supplemental regression checks.
- Model fit: the final SEM accounted for 60.8% of variance in Sustainable Consumption Behavior (SCB) — a strong fit by behavioural-research standards.
Headline finding
The two pathways operate differently:
| Pathway | Mechanism | Outcome |
|---|---|---|
| TPB | Attitude / Subjective Norms / Perceived Behavioral Control → Behavioral Intention → Sustainable Consumption Behavior | Significant — but mediated through conscious intent |
| VBN | Environmental Awareness → Altruistic & Biospheric Values → New Environmental Paradigm → Personal Norms → Sustainable Consumption Behavior | Significant and direct — bypasses conscious intent |
The VBN pathway's direct effect — Personal Norms shaping behaviour without going through deliberate intent — is the headline. In Western individualist cultures, most behavioural-tourism research finds personal norms operating through intent. Tran et al.'s Vietnamese sample shows them operating directly.
Why it matters culturally
The authors interpret this through Vietnamese collectivist cultural context. In a collectivist society:
- Communal values and social harmony carry more weight than individual preference.
- Felt moral obligations (often shaped by family expectations, community norms, social relationships) can drive behaviour without requiring conscious cost-benefit reasoning.
- "Implicit" moral commitments behave more like reflexes than like deliberate choices.
The finding doesn't prove Vietnamese tourists don't think rationally about their travel choices. It does show that moral-normative pathways have direct behavioural effects that they often don't have in Western individualist samples.
What this means for travel and tourism
1. For Vietnamese-tourist-facing operators: design defaults, not choices
The single most actionable implication of the VBN-direct-pathway finding is embed sustainability into the default experience rather than offering it as an opt-in upgrade.
- A homestay that quietly composts and uses solar lighting captures more sustainable-behaviour value than one that offers an "eco" tier alongside a standard tier.
- Cruise boats that default to no single-use plastic capture more sustainable-behaviour value than ones that ask guests to opt into a plastic-free option.
- Cooking classes that source ingredients locally and let students see the supply chain capture more sustainable-behaviour value than ones that mention sustainability in marketing copy without changing their actual practices.
For Vietnamese visitors, opt-out designs (sustainable-by-default, opt out if you want the lower-cost less-sustainable option) outperform opt-in designs.
2. For Vietnamese-tourist-facing marketing: frame as duty, not as preference
Western sustainable-tourism marketing typically uses individualist framings: "Make a difference. Travel responsibly. Be the change."
The data here suggests different framings work better for Vietnamese tourists:
- Community and family duty: "What would your children's generation say?"
- Cultural respect: "Honour the village by leaving no trace."
- Implicit moral default: "Of course. Travel this way."
These framings activate the personal-norm pathway directly, rather than asking the visitor to deliberate.
3. For international visitors: traditional choice architecture still works
The 549-respondent sample is Vietnamese-resident tourists, and the cultural mechanism is specifically collectivist. Western individualist-cultural visitors (US, UK, Australia, Northern Europe) operate more on the TPB pathway — deliberate intent matters more, opt-in choice architectures work better.
For international travellers reading this study, the practical takeaway is different:
- Your sustainable-travel choices flow more from deliberate decisions than from felt obligations. That's not better or worse — it's the way most international visitors operate.
- The choice architectures that help you (clear pricing of sustainable options, transparent operator practices, third-party certifications) are the ones that operators marketing to Western audiences should emphasise.
4. For destinations: understand which audience you're optimising for
The finding has destination-management implications. Some Vietnam destinations (Da Lat, Sapa, Mui Ne, Phu Quoc) have a heavy domestic Vietnamese visitor base. Others (Hoi An old town, Ha Long Bay overnight cruises, Ninh Binh boat tours) have a much more international visitor mix.
For domestic-skewing destinations, sustainability strategies should lean on default-and-norm design. For international-skewing destinations, choice architectures and certifications are more effective. The pattern matters for Hoi An's community-based tourism (mixed audience) and the Central Highlands (heavily domestic) very differently.
5. The 60.8% variance explained is a strong empirical foundation for further research
For comparison, behavioural-tourism research often achieves 30–50% explained variance. 60.8% is unusually high and suggests the integrated TPB+VBN model is well-suited to the Vietnamese context. Expect more Vietnam-specific behavioural research to build on this framework over 2026–2027.
Limitations & caveats
- The sample is Vietnamese-resident tourists only. International-visitor behaviour to Vietnam (and Vietnamese tourist behaviour outside Vietnam) may not fit the same model.
- "Sustainable Consumption Behavior" is a self-reported construct. The study measures what tourists say they do, not necessarily what they actually do. Behavioural validation research (observation, transaction data) would strengthen the findings.
- The VBN-direct pathway finding doesn't quantify how much of the personal-norm effect is mediated through intent versus direct. The SEM result shows direct effect; magnitude of mediation isn't fully published in the abstract.
- The 60.8% variance is on the construct of SCB, not on actual sustainable outcomes. A high explanatory model on a self-reported scale doesn't automatically translate to high outcome impact.
- Cultural framing is interpretive. The authors' attribution to Vietnamese collectivism is reasonable and consistent with broader research, but the same pattern could be partly explained by other variables (age, education, urban vs rural, religious composition) that aren't fully controlled in the public abstract.
Sources & further reading
- Primary source: Tran, T. T. T. et al. (2025). Bridging Human Behavior and Environmental Norms: A Cross-Disciplinary Approach to Sustainable Tourism in Vietnam. Sustainability, 17(10), 4496. Open-access.
- Companion behavioural research: Adapting Values-Beliefs-Norms (VBN) and Value-Identity-Personal norm (VIP) into ecotourism intention: Cat Tien National Park, Vietnam.
- Related: Tourism social sustainability in remote communities in Vietnam (ScienceDirect).
Related on this site:
- Hoi An community-based tourism sustainability — destination-level sustainability research
- Central Highlands sustainable tourism — region-level sustainability research
- Booking.com 2025 Vietnamese traveller survey — consumer-side companion data

